The theme of Fear in Macbeth - Free Essay Example

Sample details Pages: 6 Words: 1763 Downloads: 1 Date added: 2019/02/20 Category Literature Essay Level High school Tags: Macbeth Essay Did you like this example? What is fear? Why is it so impactful? Fear can be defined as â€Å"an unpleasant emotion caused by the belief that someone or something is dangerous, likely to cause pain, or a threat† (Google). Fear is one of the most powerful emotions; it creates a paranoid, vulnerable state of mind which often leads people to making decisions that they normally would not. Many literary works incorporate fear into their themes to demonstrate how it can corrupt the way a person thinks and compel them to make irrational decisions. Don’t waste time! Our writers will create an original "The theme of Fear in Macbeth" essay for you Create order William Shakespeare’s play, The Tragedy of Macbeth reveals that fear is the most powerful motivating force in existence through Lady Macbeth’s use of fear to manipulate Macbeth, and the dynamic change in each of their characters throughout the course of the play. At the beginning of Shakespeare’s play, Macbeth receives news from three witches, who claim he will be the new Thane of Cawdor and become King of Scotland. Shortly after, Macbeth indeed becomes Thane of Cawdor, which makes him confident that the witches predictions are true. After Duncan decides to make his son Malcolm heir to the throne, Macbeth questions whether or not the witches are right about him becoming the future king of Scotland and considers the fact that he could technically still be the next king if Duncan were executed. It doesn’t take long before Lady Macbeth finds out about the meeting with the witches. She sees an opportunity for Macbeth to take the throne by murdering king Duncan, but fears that he will not be man enough to actually do it. â€Å"Yet I do fear thy nature: it is too full o’ the milk of human kindness to catch the nearest way. Thou wouldst be great art not without ambition, but without the illness should attend it† (1.5.16- 20). Lady Macbeth knows her husband is afraid of her disapproval. She uses this to her advantage by telling Macbeth she doubts his ability to go through with the plan to murder King Duncan. The last thing Macbeth wants to do is disappoint his wife; he might be afraid of killing the king, but he’s even more afraid of what Lady Macbeth thinks of him. As if questioning Macbeth’s manhood wasn’t enough to convince him to get the deed done, Lady Macbeth goes on to tell Macbeth he should act like the innocent man he his to conceal his true intentions. â€Å"Look like th’innocent flower, but be the serpent under’t† (1.5.56-58). At this point, it is obvious that Lady Macbeth knows murder is not in Macbeth’s nature. Rather than considering her husband’s morals, she continues to encourage him to go through with the plan. Further into Act 1, Macbeth approaches his wife to tell her he’s having second thoughts about killing Duncan and questions what will happen if their plan fails; this doesn’t sit right with Lady Macbeth. â€Å"We fail? But screw your courage to the sticking-place, and we’ll not fail.† (1.7.59-61). Once again, Lady Macbeth makes Macbeth question his manliness for not wanting to murder Duncan which makes him doubt the way he’s feeling. Macbeth doesn’t want to betray his cousin who trusts him and cares about him but he feels pressured to prove himself as a man. When Macbeth thinks he’s seeing a dagger which leads him to Duncans bedroom, he feels compelled to kill him. Lady Macbeth’s plan seems to have been executed practically perfectly, besides a few details that she takes into her own hands. This sequence of events shows how Lady Macbeth uses Macbeth’s fear of her disapproval to manipulate him into murdering King Duncan, which proves that fear can influence people to make decisions which are not in their true nature. After murdering King Duncan, Macbeth’s paranoia sets in almost immediately. He tells Lady Macbeth about the dagger he saw before going into the king’s room and the voices he thought he heard. Lady Macbeth warns her husband that if he thinks too much about what he has done, he will go crazy, but Macbeth is already struggling to think and act normally. When Duncan’s death is revealed to the rest of the characters, Macbeth kills the guards that him and Lady Macbeth framed as the killers to make himself appear loyal to the king and to ensure that the guards could not attempt to prove their innocence. Duncan’s two sons, Malcolm and Donalbain, flea to England and Ireland in fear that they may be killed next, but this makes them look guilty. For now, Macbeth is in the clear and he is named the new King of Scotland. Banquo becomes suspicious of the witches’ prophecies and starts to wonder if Macbeth had anything to do with them coming true. Macbeth, already paranoid, begins to fear that Banquo may know what he has done. â€Å"Our fears in Banquo stick deep, and in his royalty of nature reigns that which would be feared.† (3.1.50-55). Macbeth remembers the witches saying he would become king but that Banquo’s descendants would follow after him. He understands that this means his future children would not inherit the throne, but the children of Banquo would. Macbeth becomes terrified at the thought of having murdered the king just to have someone else’s children take the throne after him; he decides to take matters into his own hands once again, and have Banquo and his son killed. Macbeth convinces two murderers to kill Banquo and Fleance in secret. The murderers kill Banquo, but Fleance escapes. Macbeth is ecstatic to hear that Banquo has been executed, but the thought of Fleance still being alive makes him feel trapped by the fear of losing his crown. Determined to get more information, Macbeth goes back to the wi tches and demands answers. First Apparition says, â€Å"Macbeth! Macbeth! Macbeth! beware Macduff; Beware the thane of Fife† (4.1.77). After hearing this, Macbeth becomes even more fearful of Macduff; he is convinced that he needs to kill him immediately to get rid of his troubles and fears. Macbeth soon discovers that Macduff ran away to England and decides to kill his family instead. At this point, Macbeth is desperately trying to secure his title as king. His actions clearly show that his morals have completely changed. In the beginning, Macbeth was hesitant about murdering Duncan; he did not want to betray his leader. Once the evil deed was done, the evil within Macbeth only grew. He has become a tyrant leader who no longer feels ashamed of his actions. Macbeth’s fear of losing power controls his thoughts and actions; he is now willing to murder anyone who stands in the way of his power. This drastic change in Macbeth’s character shows how fear can corrupt a person’s mind and motivate them to do the unthinkable. In England, Malcolm and Macduff discuss the disastrous state of Scotland. After Ross informs Macduff that his wife and children have been killed under the orders of Macbeth, he is even more prepared to get his revenge. Malcolm agrees to help Macduff save his country and tells him he has already arranged for England to help them. The leader of the English army and 10,000 of their soldiers follow Malcolm and Macduff to Scotland in hopes of defeating the evil Macbeth. Back at Macbeth’s castle in Dunsinane, Lady Macbeth has been seen acting suspiciously by a gentlewoman who works for her. Unsure of what to do, the gentlewoman reports Lady Macbeth’s strange behavior to a doctor, â€Å"Since his majesty went into the field, I have seen her rise from her bed, throw her night-gown upon her, unlock her closet, take forth paper, fold it, write upon’t, read it, afterwards seal it, and again return to bed; yet all this while in a most fast sleep.† (5.1.5-9). Lady Macb eth is beginning to feel guilty for the murder of Duncan and the murders that followed; after all, she did push Macbeth to kill Duncan knowing it was not in his nature. As Lady Macbeth realizes that she is responsible for most of her husband’s wrong-doings, she becomes overwhelmed with paranoia and guilt. The woman who once thought her and Macbeth were untouchable, has been driven to insanity. â€Å"Out, damned spot! Out, I say!—One, two. Why, then, ’tis time to do ’t. Hell is murky!—Fie, my lord, fie! A soldier, and afeard? What need we fear who knows it, when none can call our power to account?—Yet who would have thought the old man to have had so much blood in him.† (5.1.32-35). Lady Macbeth has gone mad to the point that her mind is creating visuals which do not exist. She imagines the blood of King Duncan on her hands and is incapable of washing it off. The fear of living with the guilt that she’s been carrying around for the rest of her days begins to consume her thoughts and control her life. Right before Macbeth goes to battle he is informed that his wife, the Queen, is dead. Shakespeare does not specify the cause of Lady Macbeth’s death, but it appears as if she has taken her own life. At the beginning of the play, Lady Macbeth is the more evil of the two Macbeths. She pressures Macbeth into murdering the king and encourages his sinful behavior. Eventually, she realizes the severity of her actions and loses her sanity. The way Lady Macbeth’s character shifts from being manipulative and ill-intentioned to fearful of her own thoughts proves how powerful fear can be. William Shakespeare’s play, The Tragedy of Macbeth demonstrates the theme that fear is a powerful motivator which can lead people to making unimaginable decisions. Lady Macbeth utilizes fear to make her husband go against his morals and murder King Duncan. As the play progresses, Macbeth faces some obstacles which make him fearful of losing power. Macbeth’s character undergoes drastic change; he goes from being a noble, well-respected man, to being the most evil tyrant leader Scotland has ever seen. As Macbeth becomes a different man, his wife soon realizes that she is the one to blame for the poor choices he has made since taking the throne. The fear that Lady Macbeth faces after coming to realization that she would have to live with her guilt forever affects her everyday behavior and permanently scars her. Shakespeare’s play reveals that fear leads to corruption, irrational thinking and even insanity.

Islamic accounting - Free Essay Example

Sample details Pages: 10 Words: 2938 Downloads: 8 Date added: 2017/06/26 Category Finance Essay Type Argumentative essay Did you like this example? Question 01 What distinguishes Islamic accounting and conventional accounting? Briefly discuss the additional objectives of Islamic accounting. Answer 01 It could be stated that both Islamic accounting as well as conventional accounting are both in the business of providing information to end customers. The main differences lie in the following factors: Don’t waste time! Our writers will create an original "Islamic accounting" essay for you Create order Objective of providing information Islamic accounting enables users to ensure that Islamic organizations abide by the principles of the Shariah in all of its dealings and enables the assessment of whether the objectives of the organization are being met. Type of information The type of information which Islamic accounting identifies, measures is different. Conventional accounting concentrates on identifying economic events and transactions, while Islamic accounting must identify socio-economic and religious events and transactions. Islamic accounting is more holistic in its approach as both financial and non-financial measures regarding the economic, social, environmental and religious events and transactions are measured and reported. Different statements Islamic accounting requires totally different statements altogether from that of conventional accounting. This is to de-emphasize the focus on profits by the income statement provided by conventional accounting. Users of reports Islamic accounting recognizes that all including the society are the users of the reports. The reason being that society as a whole can make corporations accountable for their actions and ensure that they comply with Shariah principles and do not harm others while making money ethically and achieve a equitable allocation and distribution of wealth among members of society especially the stakeholders of the concerned corporation. The importance of establishing objectives Accounting scholars and practitioners alike have found that the process of developing financial accounting standards without establishing objectives leads to inconsistent standards which may not be suitable for the environment in which they are expected to be applied. Agreement on the objectives of financial accounting for Islamic banks would achieve many benefits: The objectives will be used as a guide by the Financial Accounting Standards Board for Islamic Banks and Financial Institutions when developing financial accounting standards. This should assure consistency in developing standards. The objectives will assist Islamic banks, in the absence of accepted accounting standards, in making choices among alternative accounting treatments. The objectives will be available as a guide and a regulator of subjective judgment made by management when preparing the financial statements and other financial reports. The objectives, when properly defined, should increase users confidence and understanding of accounting information and, in turn, their confidence in Islamic banks. Establishing objectives should lead to the development of accounting standards which are likely to be consistent with each other. This should increase users confidence in the financial reports of Islamic banks. Financial accounting is mainly concerned with providing information to assist users in making decisions. Those who deal with Islamic banks are concerned, in the first place, with obeying and satisfying Allah in their financial and other dealings. It is natural, therefore, that there should be differences between objectives established for other banks and those to be established for Islamic banks. Those differences stem mainly from differences in the objectives of those who need accounting information and, therefore, in the information they need. This does not mean, however, that we should reject all the results of contemporary accounting thought in non-Islamic countries. This is so because there are common objectives between Muslim and non-Muslim users of accounting information. In addition to the above, there are other reasons why different objectives of financial accounting should be established for Islamic banks. Those are: Islamic banks must comply with the principles and rules of Shariah in all their financial and other dealings. The functions of Islamic banks are significantly different from those of traditional banks who have adopted the Western model of banking. The relationship between Islamic banks and the parties that deal with them differs from the relationship of those who deal with traditional banks. Two approaches to establishing objectives have emerged through the discussion which took place at different meetings of the committees established by the Board. These are: Establish objectives based on the principles of Islam and its teachings and then consider these established objectives in relation to contemporary accounting thought. Start with objectives established in contemporary accounting thought, test them against Islamic Shariah, accept those that are consistent with Shariah and reject those that are not. In order to test each approach and select an appropriate one, various efforts were put in by various Shariah scholars. Subsequent to all their efforts it was decided that the second approach be chosen to establish objectives of financial accounting for Islamic banks and financial institutions. The main categories of users of external financial reports for Islamic banks whose information needs are addressed in this statement include: Current and saving account holders. Equity holders. Holders of investment accounts. Other depositors. Others who transact business with the Islamic bank, who are not equity or account holders. Regulatory agencies. Zakah agencies. It is possible to summarize the common information needs of users as follows: Information which can assist in evaluating the banks compliance with the principles of Shariah in all of its financial and other dealings. Information which can assist in evaluating the banks ability in: Using the economic resources available to it in a manner that safeguards these resources while increasing their value, at reasonable rates. Carrying out its social responsibilities and in particular those that have been specified by Islam, including the good use of available resources, the protection of the rights of others and the prevention of corruption on earth. Providing for the economic needs of those who deal with the bank. Maintaining liquidity at appropriate levels. Information which can assist those employed by the bank in evaluating their relationship and future with the Islamic bank, including the banks ability to safeguard and develop their rights and develop their managerial and productive skills and capabilities. It is assumed that the types of information described above represent the minimum required to satisfy the common information needs of external users of financial reports. In conclusion, the following could be stated as the objectives of Islamic accounting: To determine the rights and obligations of all interested parties, including those rights and obligations resulting from incomplete transactions and other events, in accordance with the principles of Islamic Shariah and its concepts of fairness, charity and compliance with Islamic business values. To contribute to the safeguarding of the Islamic banks assets, its rights and the rights of others in an adequate manner. To contribute to the enhancement of the managerial and productive capabilities of the Islamic bank and encourage compliance with its established goals and policies and, above all, compliance with Islamic Shariah in all transactions and events. To provide, through financial reports, useful information to users of these reports, to enable them to make legitimate decisions in their dealings with Islamic banks. Question 02 Discuss the Shariah audit issues and their importance in relation to financial statements of Islamic banks. Answer 02 There are various issues in a Shariah audit that could face an Islamic financial institution. The following discussion pertains to those issues and their high relevance to the financial statements of such institutions. First and foremost, any Islamic bank that is found to have breached any of their fiduciary duties or have contravened the covenants of Shariah could be in a serious and potentially harmful situation by litigation from its investors and other third parties. Hence, to make certain Islamic banks comply properly with the requirements of Shariah principles as well as their performance of fiduciary duties and obligations, there should be very close cooperation between the Shariah Boards and the external auditors. This process will help to ensure compliance in all these respects. The term or rather the concept now commonly known as Shariah audit is now understood that the ensuring of Shariah compliance, fiduciary compliance and further the assigning of the formal resp onsibility to ensure all such compliances are in order. The Shariah audit of an Islamic financial institution is not necessarily limited to the performance by an external auditor. It could be performed by the Islamic financial institutions very own Shariah Board or by external auditors as well. If the Shariah audit is being done by the Shariah Board, they should be capable of doing the task. On one perspective, it should clearly be noted that when the Shariah audit is performed by the banks external auditors they will undoubtedly ensure adequate independence to be maintained. Further, these auditors would most definitely require knowledge, competence and expertise to cope with Shariah compliance issues and fiduciary compliance issues. On another perspective, if the Shariah audit is being carried out by the Shariah Board of the Islamic bank, they will have to ensure sufficiently or maximum independence in order to carry out a thorough and an effective audit. Like in the previou s situation, the Shariah Board will have to have knowledge, competence and expertise to cope with and solve issues relating to accounting issues and their implications. Some contemporary Islamic financial institutions have now a group of scholars known as Shariah internal auditors. These individuals are also members of the institutions Shariah Board. They on a continuous basis monitor Shariah and fiduciary compliance and report findings to the main Shariah Board. Therefore, based on the above two scenarios the Shariah Board as well the external auditors will require close liaising with each other on a continuous basis to ensure that all potential Shariah and fiduciary compliance issues, which the Islamic bank may be exposed to, are addressed and resolved on a timely and accurate basis. Finally, in order to ensure that all Islamic banks comply with all the covenants of the Shariah and perform their fiduciary duties and obligations as well towards their depositors, it is high ly important that there are proper rules and regulations established. These are important with regard to general and additional disclosure requirements in the Islamic banks financial statements, such as disclosure requirements of the: Accounting policies Disposal of non-Shariah compliance earnings Profit distribution policy Shariah advisors Zakat obligations Auditors are responsible for forming and expressing opinions on financial statements. It is also their responsibility for preparing and presenting financial statements in compliance with all Shariah rules and principles. The relevant legislation and regulations is that of the management of the financial institution. Hence, it should clearly be understood that the audit of the financial statements does not relieve the management of the financial institution of this responsibility. Thereby, indicating the importance of Shariah audit issues and their importance to the preparation of financial statements of Islamic banks. Question 03 Why is taxation an important issue for Islamic banking products? Answer 03 A common misperception created in the minds of most people nowadays is the perception of unfair taxation. Islamic banks, other than in Malaysia have developed in a relatively tax free milieu. Even countries such as Pakistan, general provisions were made to exempt from taxation for Islamic finance arranged on a cross border basis, but no specific provisions were made for within the country. It was the UK government that took a lead in the west in revising its taxation law to include specific provisions for Islamic products and services. The following is a discussion about a key taxation issue that arose in UK and how it was resolved. In fact had this issue not been properly resolved it would have derailed any plans to establish Islamic banks in the UK. The key issue relates to the tax treatment of Islamic deposit accounts that in theory paid a profit share to the depositor. Deposit accounts offered by the Islamic Bank of Britain were based on the principle of Mudharabah. Gener ally, any interest payments made by banks to its depositors is deductible from gross income before tax is calculated. However, in accordance with anti-avoidance rules in UK, any interest payments made on deposits that were linked to the profit made by a bank was not allowed to be deducted from gross income but was considered as distribution of profit after tax. In other words, these were considered as dividend payments. Example: Suppose a bank paid pound;100 on normal deposit accounts. This amount was deducted from its gross income, say pound;300. Hence, tax paid on the net amount of pound;200. If on the other hand, the pound;100 payment was linked to profit made by the bank, tax would be deducted on the gross income of pound;300 and the pound;100 was considered as distribution after tax. This of course results in much higher tax charge for the bank. The profit payment on the Islamic deposit accounts was at first considered to be linked to the profit made by the Islamic Bank of B ritain and therefore was not allowed to be deducted as an expense against gross income. This high incidence of tax charge made the Bank economically unviable. To overcome the above issue, the UK government established a special Inland Revenue task force to review the taxation of Islamic products so as to ensure that there was a level playing field with the conventional market. In the government paper, Regulatory Impact Assessment for Shariah Compliant Products that accompanied the Budget for 2005 it was stated that the key policy objective for taxation of Shariah compliant products is to ensure that such products are: ..taxed in a way that is neither more nor less advantageous than equivalent banking products. The intended effect of the proposals is to allow providers to offer Shariah compliant products without facing commercial disadvantage and to enable customers to take up these products without encountering uncertainty or disadvantage over tax treatment. The solution that emerged from the task force and included in the Finance Act 2005 was to define Islamic products as Alternative Financial Arrangements and to set out the key structures of the arrangements in the legislation. The profit payment on the deposits was termed as Profit Share Return. Islamic products are not specially mentioned in the Finance Act but only in the explanatory notes. Furthermore, the Act is concerned not with principles but the specific structures of the products. This was done to mitigate the risk of these structures being used to avoid taxation. In the explanatory notes it was clearly stated that the relevant legislative clauses relate to arrangements: that involves profits and losses on sales of assets or profit share agreements that are economically equivalent to conventional banking products, but are not interest or speculative returns. The measure ensures that such arrangements are taxed no more or less favourably than equivalent finance arrangements involving interest. In other words, profit payments made for Islamic deposits that conformed to those arrangements were deemed to be interest and hence treated for tax purposes as any interest payments. This ensured that Islamic deposits were taxed on the same basis as conventional deposits. In our above example, Islamic banks paid tax on the net pound;200 rather than the gross amount. For sake of clarity, in case of Islamic deposit the Finance Act defines the following arrangements that give rise to profit share return: The depositor deposits money with a financial institution. The money, together with money deposited with the institution by other persons, is used by the institution with a view to producing a profit. From time to time the institution makes or credits a payment to the depositor, in proportion to the amount deposited by him, out of any profit resulting from the use of the money. The payments made or credited by the institution equate, in substance, to the return on an investment of money at interest. Other than (d) above, the structure described is a Mudharabah. Similarly the Finance Act 2005 also defined an Islamic finance arrangement based on Murabahah principle and termed the equivalent profit amount charged to customers as Alternative Finance Return. Prior to 2005, the government had already resolved the issue of double incidence of Stamp Duty on property financed using Islamic structures. Normally whenever property is purchased, the buyer has to pay a Stamp Duty. In case of Islamic finance where banks buy the property and then sell to the customer, there were two Stamp Duties payable, first by the bank and then by the customer. In 2003, the government had amended the Stamp Duty rules to charge only one Stamp Duty on such finance arrangements. These rules were further refined in the Finance Act 2005. Since 2005, UK government has continued to add to the tax legislation for Islamic products. Islamic mortgages using Diminishing Musharakah arrangements, Islamic agency ac counts and recently in the Finance Bill 2006, Islamic bonds (Sukuks) have been covered. The other issue relating to tax was VAT. This has been more difficult to resolve since VAT is a European wide legislation and requires any major change at the European level. Despite this, the UK government has issued guidelines on the application of VAT to Islamic products. These guidelines have ensured that Islamic products are treated in the same way as conventional products. It is important to emphasize that the significant development outlined above in respect of taxation of Islamic products could not have been achieved had there not been commitment from Chancellor and his Treasury ministers. Importance has continued to be given to the success of Islamic finance in the UK and concerns that hinder a level playing field for the Islamic finance market are being carefully reviewed and resolved. The lead taken by UK authorities to tax Islamic products is now being considered by other author ities as possible solution to help the Islamic markets to flourish. References https://basiccollegeaccounting.com/basic-understanding-of-islamic-accounting-its-objectives-and-the-differences-between-convention-accounting/ https://www.aaoifi.com/objectives-acc.html https://www.bta.kz/files/about_fin_iconf_Session_10-taxation_2.pdf

Damaging Air Pollution - Free Essay Example

Sample details Pages: 4 Words: 1341 Downloads: 4 Date added: 2019/04/15 Category Ecology Essay Level High school Tags: Air Pollution Essay Pollution Essay Did you like this example? Introduction A survey of the available literature shows just how damaging air pollution can be to the flora and fauna that inhabit the natural world. The leading pollutants include tropospheric ozone and carbon monoxide from automobile exhaust, the burning of diesel fuel in combustion engines and coal ash from electric power plants that creates particulate matter, and nitrogen dioxide from agricultural manure and fertilizers as well as the combustion of fossil fuels. These airborne pollutants can eventually fall out of the atmosphere and deposit onto the land and bodies of water. Don’t waste time! Our writers will create an original "Damaging Air Pollution" essay for you Create order The uptake, inhalation or consumption of these pollutants can be harmful to many plant and animal species such as the birch, pine, and maple trees of the temperate forest, the mice, birds, and fish of the urban ecosystem, and the fish, insects, and crayfish of the aquatic ecosystem. The role of air pollution in biodiversity, local habitat modification, and climate change are also examined. A survey of the worlds biomes Several of the Earths biomes will be referred to in the pages to come. It is therefore important to have an understanding of the biomes as it pertains to what makes a biome and why they are where they are. Climate, topography, and soil and parallel influences in aquatic environments- determine the changing character of plant and animal life over the surface of Earth. Although no two locations harbor exactly the same assemblage of species, we can group biological communities in categories based on their dominant plant forms, which give communities their overall character. These categories are referred to as biomes (Ricklefs 99). Contributions of Heinrich Walter German ecologist Heinrich Walter devised a terrestrial classification system which he termed ?climate zones. These zones were broken down by annual precipitation and temperature trends across the globe. He was careful to note signature plant and or animal traits that seemed to occupy these zones (Ricklefs). Contributions of Robert H. Whitaker Robert H. Whitaker, an ecologist from Cornell University, would devise his own classification system with a slight twist. He first established the vegetative structure of biome, then developed a diagram on which he plotted the annual precipitation and temperature norms. It should be noted that in the intermediaries between forest and desert, he took into account soil type, seasonal climate patterns, and fire to determine woodlands, shrublands, and grassland locations (Ricklefs). Courtesy of The Economy of Nature by Robert E. Ricklefs It is important to note the following when it comes to the animals and plants that share a biome: (1) animals and plants adapt to match their environments, (2) some fauna and flora overlap at the boundaries between neighboring biomes in response to local climate feedback loops, (3) while climate is the key factor in determining plant distribution, soil types and changes in topography are also influences, and (4) aquatic biomes are classified by salinity, water flow rate and water depth rather than temperature, precipitation and vegetation structure (Ricklefs). A biome map of the world courtesy of The Economy of Nature by Robert E. Ricklefs. The demarcations more or less follow Heinrich Walters biome structure. Walter noted the boreal and polar zones have annual average temperatures below 5, the temperate regions experience annual average temperatures between 5 and 20(central Ohio is located in the Temperate seasonal forest), and the tropical and equatorial biomes exceed 20 as an annual average temperature. Nitrogen Dioxide (NO2 or Nitrite) Pollution In the aquatic ecosystem The three major pollutants of freshwater ecosystems are sulfur dioxide (SO2), nitrogen oxide (NO), and nitrogen dioxide (NO2). The most common non-point sources of airborne NO2 pollution are the volatilization of manure and fertilizers and the combustion of fossil fuels. Airborne NO2 can enter the aquatic ecosystem by depositing on lakes, streams, and rivers. If introduced, nitrite can exhibit lethal toxicity of fish and invertebrates in doses of 3 mg NO2-N/L in a 96-hour exposure time (Camargo and Alonzo, 2006). This is mainly achieved by rendering oxygen-carrying cells incapable of transporting oxygen. This results in hypoxia and death in fish and crayfish. Nitrite can also be toxic in the following ways: reduction of Cl- ions in and outside of cells causing an imbalance of electrolytes, reduced function of cardiac and skeletal muscles and decreased neurotransmission from imbalance of K+ , formation of mutagenic and carcinogenic N-nitroso compounds, acute damage to mitochondria in liver cells contributing to free oxygen shortage in the tissue, and a compromised immune system leading to increased susceptibility to parasites and infections diseases (Camargo and Alonzo, 2006). Nitrite can, through chemical reactions with other materials in the water, produce compounds that have lasting, disruptive effects. Nitrite lowers the pH of lakes and streams making them more acidic. According to Bobbink et al., fresh waters are among the most sensitive ecosystems with respect to atmospheric acidification (1998, p.718). Acidification of water that has low turnover rates, specifically lakes, can upset the delicate balance of nutrient cycles (and therefore food chain) required for the ecosystem to function properly. Low pH can also encourage the development of toxic algae which starves the other organisms of dissolved oxygen in a process called eutrophication. With low availability of food and oxygen, reproductive rates of aquatic animals suffer. Eutrophication reduces water clarity and light availability which can negatively impact photosynthesis rates in aquatic plant life (Hernandez et al., 2016). According to Camargo and Alonzo, Anthropogenic discharges containing elevated nitrite concentrations have been associated with fish kills in aquatic ecosystems (Camargo and Alonzo, 2006, p. 840). The US Fish and Wildlife Service (FWS) lists vertebrate species impacted by reactive nitrogen. In the FWS Great Lakes Big River region there are five (5) such species. The Jollyville plateau salamander and the Smalleye shiner are listed as ?potentially endangered due to direct toxicity or lethal effects of N and eutrophication causing algal blooms that alter habitat by covering up substrate, respectively. The other three (3) species are listed as ?threatened by the FWS: the Arkansas River shiner and the Neosho Madtom for eutrophication lowering dissolved oxygen levels, and the Desert Tortoise (Sonoran population) for N pollution increasing non-native plant species that kill off the tortoises food sources (Hernandez et al., 2016). In species-rich grasslands Some nitrogen deposition studies have been conducted in western and central Europe concerning pH neutral grasslands which are moist to semi arid (Bobbink et al., 1998). This biome type tends to have soil that is nitrogen-poor hence the need for fertilization. In the UK, the Park Grass experiment has been ongoing since 1856 (Williams, 1978 and Dodd et al., 1994 as cited by Bobbink et al., 1998). Enrichment of nitrogen as sodium nitrate fertilizer is applied to select plots of neutral grassland in the amount of 48 kg N per hectare per year. This has resulted in a population explosion of a few, nitrophilic grasses such as the Meadow foxtail grass (Alopecurus pratensis) and Tall oat-grass (Arrhenatherum elatius). These have crowded out the abundance of smaller, more regular perennials (Bobbink et al., 1998). Additional land management is necessary to reintroduce and maintain biodiversity. In forest ground vegetation Drastic changes in ground flora have been noted in many studies over the years due to acidification of nutrient-poor soil by airborne nitrogen deposition. In their 1989 study of a central Netherlands forest, Dirkse Van Dobben observed a disappearance of all lichen species when nitrogen deposition increased from around 20 kg N per hectare per year in 1958 to near 40 kg N per hectare per year by 1981 (Bobbink et al., 1998). In a semi-natural forest in northeastern France, a large increase in nitrophilic plants was observed on 50 permanent vegetation plots when nitrogen deposition of 15-20 kg N per hectare per year raised soil pH to 6.9 (Thimonier et al., 1994). Coniferous forests have also been impacted by increased nitrogen inputs. The shoot density of Wavy hair-grass (D. flexousa) showed significant increase in a central Sweden coniferous forest where experimental ammonium nitrate enrichment reached 10 kg N per hectare per year (Kellner Redbo-Torstensson, 1995). This along with s imilar results in Finland seems to point to decreased biomass of shrubs and mosses that thrive in nutrient-poor areas. Competitive exclusion modifies the local, vegetative landscape to favor grasses and mosses that prosper in nutrient-rich soils. (Bobbink et al., 1998).

Language And Development Of Language, Experience,...

Language plays a significant role in the process of transmitting knowledge and culture among mankind. Everyone learns a language at the early stages of life. From birth to seven years, a tremendous development of language skills is seen in a child. The essay states the various developmental phases of phonetics, morphology, semantics and syntax in a child. The behaviourist and cognitive theories states that nature and nurture plays a vital role in this process. The essay also throws light on the importance of culture, experience, maturation and readiness with the aid of theories laid by Lev Vygotsky and Jean Piaget. Language is explained as the communication among human beings. Human communication can be either spoken or written†¦show more content†¦From this stage a child even begins to grasp the meaning of short phrases such as #39;give me#39;, do not touch#39; and the like. In the next phase of language development, the child articulates words. The child picks up simple words from its surroundings and that which may be taught him. He associates the words with its meaning (Kuhl et al., 2016). The development of semantic skills take place here. In the later phase, sentence formation begins. In the beginning, grammar and the conventional way of sentence structure is lacked. From here commences the syntactic development in an individual. Through experiences and expressions, the child unknowingly adapts to the accepted grammar and conventional sentence construction rules of its language ((Bloom, 1993). By the age of four a child speaks and understands his language clearly. A child is inspired by surroundings to develop its language skills. He or she imitates and reacts to the sounds around them. B. F. Skinner, one of the pioneers of behaviourism, emphasizes the role of environment in language development (Sommerville, 2006). He argues that a child learns words by associating it with meanings. The word #39;cat#39; brings the idea of that particular animal in the child#39;s mind. Children imitate words and sentences used by parents and elders. According to him, children learn language on the basis of reinforcement principles. Adults surrounding them, especially parents and siblings, correct and

Sheet Metal Design Site Map Free Essays

string(30) " in the graphical combo list\." Sheet Metal Design Site Map Preface Using This Product More Information What’s New? Getting Started Entering the Workbench Defining the Parameters Creating the First Wall Creating the Side Walls Creating a Cutout Creating Automatic Bends Unfolding the Part Extracting Drawings Basic Tasks Managing the Default Parameters Editing the Parameters Bend Extremities Bend Corner Relief Bend Allowance Creating Walls From an Existing Solid From a Sketch Tangent Walls From an Edge Extruding Isolating Walls Creating Rolled Walls Creating Bends Site Map http://arbredsy/FmoCXR8/SheEnglish/sheug. oc/src/sheugsm. htm (1 of 4) [12/7/2001 5:13:18 PM] Bends from Walls Automatic Bends Conical Bends Bends From Line Creating Swept Walls Creating a Flange Creating a Hem Creating a Tear Drop Creating a Swept Flange Redefining Swept Walls Limits Displaying Swept Walls Axes Unfolding Folded/Unfolded View Access Concurrent Access Creating a Cutout Stamping Standard Features Point Stamp Extruded Hole Curv e Stamp Surface Stamp Bridge Louver Stiffness Rib Creating User-defined Stamping Features Punch and Matrix Opening and Cutting faces Editing User-Defined Stamps Patterning Site Map ttp://arbredsy/FmoCXR8/SheEnglish/sheug. We will write a custom essay sample on Sheet Metal Design Site Map or any similar topic only for you Order Now doc/src/sheugsm. htm (2 of 4) [12/7/2001 5:13:18 PM] Rectangular Patterns Circular Patterns User-Defined Patterns Corner Relief Redefining a Corner Relief Creating a Local Corner Relief Creating Corners Creating Chamfers Mapping Elements Saving As DXF Reference Elements Advanced Tasks Integration with Part Design Designing in Context Designing†¦ Modifying†¦ PowerCopies Management Creating PowerCopies Instantiating PowerCopies Saving PowerCopies Looking For Sheet Metal Features Workbench Description Menu Bar Sheet Metal Toolbar Constraints Toolbar Reference Elements Toolbar Specification Tree Customizing Site Map http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugsm. htm (3 of 4) [12/7/2001 5:13:18 PM] Glossary Index Site Map http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugsm. htm (4 of 4) [12/7/2001 5:13:18 PM] Preface The V5 CATIA – Sheet Metal Design is a new generation product offering an intuitive and flexible user interface. It provides an associative feature-based modeling making it possible to design sheet metal parts in concurrent engineering between the unfolded or folded part representation. V5R7 CATIA – Sheet Metal Design offers the following main functions: Associative and dedicated Sheet Metal feature based modeling Concurrent engineering between the unfolded or folded part representation Access to company defined standards tables Dedicated drawing capability including unfolded view and specific settings. All sheetmetal specifications can be re-used by the CATIA – Knowledge Advisor to capture corporate knowledge and increase the quality of designs. Natively integrated, CATIA – Sheet Metal Design offers the same ease of use and user interface consistency as all CATIA V5 applications. As a scalable product, CATIA Version 5 Sheet Metal Design can be used in cooperation with other current or future companion products in the next CATIA generation such as CATIA Version 5 Assembly Design and CATIA Version 5 Generative Drafting. The widest application portfolio in the industry is also accessible through interoperability with CATIA Solutions Version 4 to enable support of the full product development process from initial concept to product in operation. Using This Product More Information Preface http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugpr01. htm [12/7/2001 5:13:19 PM] Using This Product This guide is intended for the user who needs to become quickly familiar with the CATIA Version 5 Sheet Metal Design product. The user should be familiar with basic Version 5 concepts such as document windows, standard and view toolbars. To get the most out of this guide, we suggest you start reading and performing the step-by-step tutorial â€Å"Getting Started†. The next sections deal with the handling of more detailed capabilities of the product. Using This Product http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugpr03. htm [12/7/2001 5:13:19 PM] Where to Find More Information Prior to reading this book, we recommend that you read the Infrastructure User’s Guide. The Part Design User’s Guide, the Assembly Design User’s Guide and the Generative Drafting User’s Guide may prove useful. Finally, you can read the Sheet Metal Production User’s Guide to find out more about that product and to fully use the interoperability between the two products. Conventions More Information http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugpr04. htm [12/7/2001 5:13:19 PM] What’s New? This table identifies what new or improved capabilities have been documented in Version 5 Release 8 of the Sheet Metal Design workbench. Basic Tasks New: Creating chamfers New: Displaying swept wall axes New: Saving as DXF Enhanced: Creating walls from an existing Part Enhanced: Creating walls from an edge Enhanced: Extruding Enhanced: Defining bend extremities when manually creating bends from walls or automatically creating them Enhanced: Stamping Enhanced: User interface of user-defined stamping features (punch and die and cut-out and opening faces). Enhanced: Choice of convex/concave edges when creating corners Enhanced: Mapping elements Advanced Tasks Enhanced: Creating PowerCopy Features Enhanced: Instantiating PowerCopy Features What’s New? http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugwn. htm [12/7/2001 5:13:19 PM] Getting Started Before getting into the detailed instructions for using Version 5 CATIA – Sheet Metal Design, the following tutorial provides a step-by-step scenario demonstrating how to use key functionalities. The main tasks proposed in this section are: Entering the Workbench Defining the Parameters Creating the First Wall Creating the Side Walls Creating a Cutout Creating Automatic Bends Unfolding the Part Extracting Drawings All together, these tasks should take about 15 minutes to complete. Getting Started ttp://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheuggs01. htm [12/7/2001 5:13:19 PM] Entering the Sheet Metal Workbench The Sheet Metal Design functions are available when you are in the Part environment. Several functions are integrated from the Part Design workbench. This task shows how to enter the workbench. Choose the Mechanical Design - Sheet Metal Design it em from the Start menu. The Sheet Metal toolbar is displayed and ready to use. You may add the Sheet Metal Design workbench to your Favorites, using the Tools - Customize item. For more information, refer to the Infrastructure User’s Guide. Entering the Workbench http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheuggs00. htm (1 of 2) [12/7/2001 5:13:20 PM] Defining the Sheet Metal Parameters This task shows you how to configure the sheet metal parameters. 1. Click the Sheet Metal Parameters icon . The Sheet Metal Parameters dialog box is displayed. 2. Enter 1mm in the Thickness field. 3. Enter 5mm in the Bend Radius field. 4. Select the Bend Extremities tab. 5. Select Tangent in the Bend Extremities combo list. An alternative is to select the bend type in the graphical combo list. You read "Sheet Metal Design Site Map" in category "Papers" Click OK to validate the parameters and close the dialog box. The Sheet Metal Parameters feature is added in the specification tree. 6. Defining the Parameters http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheuggs02. htm (1 of 2) [12/7/2001 5:13:20 PM] The other two tabs are not used in this scenario. Defining the Parameters http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheuggs02. htm (2 of 2) [12/7/2001 5:13:20 PM] Creating the First Wall This task shows how to create the first wall of the Sheet Metal Part. 1. Click the Sketcher icon then select the xy plane. 2. Select the Profile icon . 3. Sketch the contour as shown below: Click the Exit workbench icon to return to the 3D world. The sketch remains selected. 4. Click the Wall icon . The Wall Definition dialog box opens. 5. Creating the First Wall http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheuggs03. htm (1 of 2) [12/7/2001 5:13:20 PM] By default, the Material Side is set to the top. Click OK. The Wall. 1 feature is added in the specification tree 6. The first wall of the Sheet Metal Part is known as the Reference wall. Creating the First Wall http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheuggs03. htm (2 of 2) [12/7/2001 5:13:20 PM] Creating the Side Walls This task shows you how to add other walls to the Sheet Metal part. Click the Wall on Edge icon . The Wall On Edge Definition dialog box opens. 1. 2. Select the left edge. Enter 50mm in the Value field. The application previews the wall. 3. By default, the material side is such that it ensures a continuity with the reference profile. If needed, invert it using the Reverse side button, or clicking the arrow. 4. Click the Reverse Position button to Invert the sketch profile. Click OK. The wall is created and the Wall On Edge. 1 feature is displayed in the specification tree: 5. Creating the Side Walls http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheuggs04. htm (1 of 3) [12/7/2001 5:13:21 PM] 6. Select the right edge. Click the Wall on Edge icon again. The Wall On Edge Definition dialog box opens with the parameters previously selected. 7. 8. Invert the sketch profile and click OK to validate. Click the Wall on Edge icon again. 9. Select the front edge. The Wall Definition dialog box opens with the parameters previously selected. 10. Enter 30mm in the Value field and 10mm in the Limit1 and Limit2 fields, then invert the sketch profile. 11. 12. Press OK to validate. Creating the Side Walls http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheuggs04. htm (2 of 3) [12/7/2001 5:13:21 PM] The final part looks like this: Creating the Side Walls ttp://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheuggs04. htm (3 of 3) [12/7/2001 5:13:21 PM] Creating a Cutout In this task, you will learn how to: open a sketch on an existing face define a contour in order to create a cutout. Select Wall On Edge. 2 from the geometry area to define the working plane. 1. 2. Click the Sketcher icon . 3. Click the Elongated Hole icon to create the contour. To access the oblong profile, click the black triangle on the Rectangle icon. It displays a secondary toolbar. Click to create the first point and drag the cursor. 4. Click to create the second point. The first semi-axis of the rofile is created. 5. Drag the cursor and click to create the third point. The second semi-axis is created and the oblong profile is displayed. 6. 7. Click the Exit workbench icon to return to the 3D world. Creating a Cutout http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheuggs05. htm (1 of 2) [12/7/2001 5:13:21 PM] 8. Select the Cutout icon . The Pocket Definition dialog box is displayed and a cutout is previewed with default parameters. 9. Set the Type to Up to last option to define the limit of your cutout. This means that the application will limit the cutout onto the last possible face, that is the opposite wall. 0. Click OK. This is your cutout: Creating a Cutout http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheuggs0 5. htm (2 of 2) [12/7/2001 5:13:21 PM] Creating the Bends Automatically This task shows how to create the bends automatically. Click the Automatic Bends icon . The bends are created. 1. CATIA displays the bends creation in the specification tree: Automatic Bends. 1 The Sheet Metal part looks like this: Creating Automatic Bends http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheuggs06. htm [12/7/2001 5:13:21 PM] Unfolding the Sheet Metal Part This task shows how to unfold the part. 1. Click the Unfold icon . The part is unfolded according to the reference wall plane, as shown below. Note that the bend limits are displayed in the unfolded view. To refold the part, click the Unfold icon again. Unfolding the Part http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheuggs07. htm [12/7/2001 5:13:21 PM] Extracting Drawings from the Sheet Metal Part This task shows how to create the Sheet Metal Part views in the Generative Drafting workbench. The Sheet Metal part is displayed. 1. Click or select File -; New†¦ 2. Select the Drawing type and click OK. The Generative Drafting workbench is launched. The New Drawing dialog box opens. 3. Click OK. For more information about this workbench, refer to Generative Drafting User’s Guide. 4. The drawing sheet appears. 5. Tile the windows horizontally using the Window - Tile Horizontally menu item. 6. Select the Unfolded View icon in the Projections toolbar from Generative Drafting Workbench. This icon is added to the Projections toolbar provided the Sheet Metal workbench is present. Choose the xy plane in the Sheet Metal specification tree. The unfolded view is displayed with the bends axes and limits. 7. Eventually, the Drafting sheet looks like this: Extracting Drawings http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheuggs08. htm (1 of 2) [12/7/2001 5:13:22 PM] Extracting Drawings http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheuggs08. htm (2 of 2) [12/7/2001 5:13:22 PM] Basic Tasks The Basic Tasks section explains how to create and modify various kinds of features. Managing the Default Parameters Creating Walls Extruding Isolating Walls Creating Rolled Walls Creating Bends Creating Swept Walls Unfolding Creating a Cutout Stamping Patterning Corner Relief Creating Corners Creating Chamfers Mapping Elements Saving As DXF Reference Elements Basic Tasks ttp://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0000. htm [12/7/2001 5:13:22 PM] Managing the Default Parameters This section explains and illustrates how to use or modify various kinds of features. The table below lists the information you will find. Using Sheet Metal Design assumes that you are in a CATPart document. Edit the parameters: select the Parameters tab e t the wall thickness and bend radius values. Modify the bend extremities : select the Bend Extremities tab and choose a predefined bend type. Define the bend corner relief: select the Bend Corner Relief tab and choose a predefined corner relief type. Define the bend allowance: select the Bend Allowance tab and define the allowance value (K factor). Managing the Default Parameters http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0100. htm [12/7/2001 5:13:22 PM] Editing the Sheet and Tool Parameters This section explains how to change the different sheet metal parameters. Click the Sheet Metal Parameters icon . 1. The Sheet Metal Parameters dialog box is displayed. 2. Change the Thickness if needed. 3. Change the Bend Radius if needed. Convention dictates that the inner angle between the two walls is used to define the bend. It can vary from 0 ° to 180 ° exclusive. This angle is constant and the bend axis is rectilinear. Press the Sheet Standards Files†¦ button to access to the company defined standards, if need be. For more information, refer to the Customizing section. 4. 5. Click OK to validate the Sheet Metal Parameters. When the Check all bend radius button is checked, and you click OK in the Sheet Metal Parameters dialog box, a list is displayed with all the bends the part that do not use the standard Bend Radius value as defined in step 3. Editing the Parameters http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0101. htm [12/7/2001 5:13:22 PM] Modifying the Bend Extremities This section explains how to change the bend extremities. Click the Sheet Metal Parameters icon . The Sheet Metal Parameters dialog box is displayed. 1. The second tab concerns the bend extremities. A combo box displays the six possible axial relimitations for the straight bend: These options can also be accessed through the pop-up button: Bend Extremities http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0103. htm (1 of 2) [12/7/2001 5:13:22 PM] Maximum: the bend is calculated between the furthest opposite edges of the supporting walls. Bend Extremities http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0103. tm (2 of 2) [12/7/2001 5:13:22 PM] Minimum with no relief: the bend corresponds to the common area of the supporting walls along the bend axis. Square relief: a square relief is added to the bend extremity. The L1 and L2 parameters can be modified if need be. Round relief: a round relief is added to the bend extremity. The L1 and L2 parameters can be modified if ne ed be. Linear: the unfolded bend is split by two planes going through the corresponding limit points (obtained by projection of the bend axis onto the edges of the supporting walls). Tangent: the edges of the bend are tangent to the edges of the supporting walls. Bend Corner Relief This section explains how to change the bend corner relief. Open the CornerRelief01. CAPTPart model from the samples directory. Within the Tools - Options - General - Parameters - Knowledge tab, check the Load Extended Language Libraries option. See Customizing Knowledgeware Applications. Click the Sheet Metal Parameters icon . 1. The Sheet Metal Parameters dialog box is displayed. The third tab concerns the bend corner relief. By default, no corner relief is created when a bend is created. Check the Automatic corner relief creation option to activate this creation every time a bend is created. Three corner relief types are available. Select the icon corresponding to the requested type: : square: the square corner relief is created using the bend limits. Its dimensions are defined by the width of the unfolded bends. : circular: its center is located at the intersection of the bend axes. For that option, a radius is proposed by default. It is equal to the bend radius + the thickness. To change it: Selecting Formula - Deactivate from the contextual menu of the input field and enter a new value, clicking on the button and entering a new formula. Bend Corner Relief http://arbredsy/FmoCXR8/SheEnglish/sheug. oc/src/sheugbt0104. htm (1 of 3) [12/7/2001 5:13:23 PM] : triangular: the triangular relief is created from the intersection point of the inner bend limits towards the intersection points of the outer bend limits with each wall. The corner relief is not previewed during its creation. The corner relief is taken into account in the unfolded view. For better result, you should s elect the Maximum Bend Extremities option when creating corner relief. These parameters are applied to each corner relief created or to be created, except to those with that have been redefined, or the locally defined corner relieves. Bend Corner Relief http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0104. htm (2 of 3) [12/7/2001 5:13:23 PM] Defining the Bend Allowance This section explains the calculations related to folding/unfolding operations. Click the Parameters icon . 1. The Sheet Metal Parameters dialog box is displayed. The fourth tab concerns the bend allowance. When a bend is unfolded, the sheet metal deformation is represented by the bend allowance V, defined by the formula: L = A + B + V where: L is the total unfolded length A and B the dimensioning lengths as defined on the figures below: bend 90 ° bend 90 ° Bend Allowance http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0102. htm (1 of 3) [12/7/2001 5:13:23 PM] Another way to compute the sheet metal deformation is the neutral fiber definition (K Factor): W = a * (R + k * T) where: W is the flat bend width R the inner bend radius T the sheet metal thickness a the inner bend angle in radians. If b is the opening bend angle in degrees: a = p * (180 – b) / 180 Physically, the neutral fiber represents the limit between the material compressed area inside the bend and the extended area outside the bend. Ideally, it is represented by an arc located inside the thickness and entered on the bend axis. Therefore the K Factor always has a value between 0 and 0. 5. When you define the sheet metal parameters, a literal feature defines the default K Factor, according to the DIN standard: K = (0. 65 + log(R / T) / 2) / 2 This formula can be deactivated or modified using Knowledge Advisor workbench. When a bend is created, the bend K Fact or and the bend allowance literals are created. Two cases may then occur: If the Sheet Metal K Factor has an activated formula and uses the default bend radius as input parameter, the same formula is activated on the bend K Factor with the bend radius as input. Else the bend K Factor is a formula equal to the Sheet Metal K Factor. The bend allowance literal is equal to a formula representing the use of the bend K Factor. This formula is fairly complex and it is strongly recommended not to delete it. V = a * (R + k * T) – 2 * (R + T) * tan ( min(p/2,a) / 2) Though it is possible to deactivate the formula to enter a fixed value. Finally, the bend flat width is computed from the bend allowance value. The bend allowance can be locally redefined when creating bends from walls, generating bends automatically, Bend Allowance http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0102. tm (2 of 3) [12/7/2001 5:13:23 PM] Creating Walls This section explains and illustrates different methods to create walls. Create walls from an existing Part: click the icon, and select a face of a wall Create a wall from a sketch: use the sketcher to define the profile, and set the material side. Create a wall tangent to another one: select a profile coinci dent with an existing wall, and select the wall to which it should be tangent Create a wall from an edge: select a wall edge, set the height, limits, angle, then the sketch and material sides Creating walls http://arbredsy/FmoCXR8/SheEnglish/sheug. oc/src/sheugbt0800. htm [12/7/2001 5:13:23 PM] Creating Walls From an Existing Part This task illustrates how to create a Sheet Metal part using an existing Part, that is recognizing the thin part shapes of the Part as created using the Part Design workbench or from a CATIA Version 4 Solid for example. Open the WallScenario1. CATPart document from the samples directory. The document contains a Part created in the Part Design workbench and it looks like this: 1. Click the Walls Recognition icon 2. Click any face to be the reference wall. The Walls Recognition Definition dialog box is displayed. 3. Choose the Wall creation mode: Part body recognition: the whole solid is processed and walls are created wherever possible Only selected faces: only explicitly selected faces of the solid are processed and the corresponding walls are created. The Reference wall is indicated in the Walls Recognition Definition dialog box for information only (it is grayed out). From an Existing Solid http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0201. htm (1 of 3) [12/7/2001 5:13:23 PM] Select faces as the Compulsory walls. These are faces from which the walls are to be generated when there might be an ambiguity. For example, if the initial part is a box, you will need to select two opposite inner faces and outer faces on the other two sides of the box, in order to avoid overlapping when generating the walls. 4. 5. Set the Internal profiles recognition mode: As cut out wall: generates walls with inner contours (no cutout feature is generated) One cut out by wall: regardless of how many pockets there are on a face of the solid, only one cutout feature is generated per wall One cut out by profile: for each inner contour on the sketch-based solid, a cutout feature is generated None: whether there are pockets on the solid aces, or not, no cutout feature is created in the resulting SheetMetal features. The Generate Bends check button allows the automatic creation of bends as the walls are being created, wherever applicable. 6. Click Apply. The walls are generated from the Part Design geometry. The Walls Recognition. 1 feature is added to the tree view. At the same time, the Sheet Metal parameters are created, deduced from the Part geometry. Select the icon to display the sheet metal parameters: 7. the Thickness is equal to 1mm the Bend radius is twice the thickness value the Bend Extremities field is set to Square relief. From an Existing Solid http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0201. htm (2 of 3) [12/7/2001 5:13:23 PM] You can modify a few of these parameters The Thickness parameter cannot be modified because it is based, like the bend extremities and radius, on the initial solid geometry . However you can modify these parameters (bend radius and bend extremities) to be taken into account for sheet metal features other than the â€Å"recognized† ones. The bend allowance, being used to unfold the part, and the corner relief affect all features, and therefore can be edited even for â€Å"recognized† features. . Click OK in the Sheet Metal Parameters when all parameters have been redefined where needed. The solid is now a Sheet Metal part. All the features are displayed in the specification tree. Once the solid has been converted to a Sheet Metal part, you can create bends as with any other Sheet Metal part, or modify/add Sheet Metal features to complete the design. U ncheck the Generate Bends button, if you do not wish bends to be created automatically. From an Existing Solid http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0201. htm (3 of 3) [12/7/2001 5:13:23 PM] Creating Walls from a Sketch This task shows how to create a wall from a sketch. You must be in the Sheet Metal Workbench, with a . CATPart document open, and you must have defined the Sheet Metal parameters. Set the sketcher grid to H = 100mm and V = 100mm, using the Tools - Options, Mechanical Design - Sketcher, Sketcher tab. 1. Click the Sketcher icon then select the xy plane. 2. Select the Profile icon . 3. Sketch the contour as shown below: 4. Click the Exit workbench icon to return to the 3D world. Click the Wall icon . The Wall Definition dialog box opens. 5. By default, the Material Side is set to the top. From a Sketch http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0801. htm (1 of 3) [12/7/2001 5:13:24 PM] Click OK. The Wall. 1 feature is added in the specification tree. 6. The first wall of the Sheet Metal Part is known as the Reference wall. Click the sketcher icon from the Wall Definition dialog box, if you wish to directly edit the selected sketch. When exiting the sketcher, you then go back to the wall creation step, without having to reactivate the Wall icon. This is also very useful if you have selected an edge from a wall and clicked the Wall icon . In this case, the sketcher is utomatically activated and the plane defined as being the selected edge’s plane. You can then directly draw a sketch, then exit the sketcher and return to the wall creation step. From a Sketch http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0801. htm (2 of 3) [12/7/2001 5:13:24 PM] You can directly create a wall with a hole, by selecting a sketch with an inner contour (the con tours must not intersect): Sketch with inner contour Resulting wall Note however, that the emptied area is part of the wall and is not a separate cutout that can be edited. From a Sketch ttp://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0801. htm (3 of 3) [12/7/2001 5:13:24 PM] Creating Tangent Walls This task shows how to create a wall tangent to a planar part of another wall or of a flange. This capability will then allow this tangent wall to be seen when unfolding the part, even though there is no bend linking it to its tangent support, provided this support is unfoldable too. Open the TangentWall1. CATPart document from the samples directory. Select a face of an existing wall and click the Sketcher icon . Here we selected the flange’s planar face. 1. 2. Select the Profile icon and sketch the contour as shown below: Using the Constraint Defined in Dialog box icon, set coincidence constraints between the edges where the support and sketch are to coincide. 3. 4. Click the Exit workbench icon to return to the 3D world. Make sure the sketch is still active, then click the Wall icon . 5. The Wall Definition dialog box opens. Tangent Walls http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0803. htm (1 of 3) [12/7/2001 5:13:24 PM] Note the orientation of the wall to be created. Click inside the Tangent to field, then select the wall to hich the new wall has to be tangent. 6. Here, you need to select the planar face of the flange. Note that the orientation automatically changes to conform to the material orientation already defined on the support wall. Click OK. The wall is created and a Wall. xxx feature is added in the specification tree. 7. Tangent Walls http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0803. htm (2 of 3) [1 2/7/2001 5:13:24 PM] If you want to create the wall on a wall that cannot be unfolded, the system issues a warning and prevents you from creating the tangent wall. Tangent Walls ttp://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0803. htm (3 of 3) [12/7/2001 5:13:24 PM] Click the Unfold icon . The tangent wall is unfolded as a wall linked by a bend to another wall, would be. 8. Creating Walls From An Edge This task shows how to create walls from edges of an existing wall. This function is used to create a box in an easy and quick way from an existing reference wall. At least one wall must already exist. Open the Wall1. CATPart document from the samples directory. Click the Wall on Edge icon and select an edge of an existing wall. 1. The Wall On Edge Definition dialog box is displayed together with a preview of the wall. Define the type of wall to be created by specifying the Reference, that is: 2. the Height of the wall: that is the orthogonal projection from the top of the wall on edge to the reference wall. Select the icon to define the height of the wall from the bottom of the reference wall or the icon to define the height of the wall from the top of the reference wall. the Length of the wall: that is the absolute value of the wall on edge without bend. From an Edge http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0802. tm (1 of 6) [12/7/2001 5:13:25 PM] the limits of the wall: LIM1 and LIM2. These texts only indicate on which side a given limit is. They are not precisely on the limit spots. The actual locations of the limits are defined with the icons and an input distance that is taken into account respectively from the inner side of an existing bend, the inner side of an existing wall or the outer side of an exist ing wall. the angle of the wall: by default it is perpendicular to the plane containing the edge. You may modify it according to your needs. it is updated dynamically on the screen. This preview gives information about: he Sketch Profile: by default, if you pick an edge on the top of the reference wall, the direction of the wall is upwards, if you pick an edge on the bottom of the reference wall the direction of the wall is downwards. Preview with top edge selected Preview with bottom edge selected You can invert the sketch’s position, and therefore the wall’s, using the Reverse Position button. Preview with bottom edge selected and sketch profile inverted From an Edge http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0802. htm (2 of 6) [12/7/2001 5:13:25 PM] the material side: by default the aterial side is proposed so as to keep a continuity with the reference profile. However, you can change it by clicking the red arrow or the Reverse Side button. Check the C learance option to offset the wall on edge from the selected edge. 3. The entered value is the radius of the bend on this edge. Wall on edge with clearance Wall on edge without clearance Note that the reference wall remains unchanged when changing the bend radius value. It is the Wall on Edge’s length that is affected. You can also choose to create the wall with or without a bend by checking the With Bend option. 4. If there is no wall from which a limit can be computed, the reference element is the edge of the reference wall. From an Edge http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0802. htm (3 of 6) [12/7/2001 5:13:25 PM] A wall on edge is defined by the selected edge (reference edge). When the reference edge is modified, by adding any feature that shortens the edge (a bend to an adjacent wall on edge or a cutout for example) the wall on edge based on this reference edge is recomputed. To avoid this you may: create the bend manually on the wall modifying the edge used as the reference to create the other wall eorder the creation of walls to postpone the creation of the modifying feature Both limits are computed with the same reference icon. The bend is not previewed, even if the option With Bend is checked. However it will be created. The selected options are modal and will be proposed to create the next wall. Walls on edge being contextual features, if you break the profiles cont inuity by inverting the material side of a wall, you may have to manually re-specify all features based upon the modified one, even if they are not directly connected to the modified wall, in order to update the part afterwards. This is the case when creating a wall on edge from another wall on edge, for example: From an Edge http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0802. htm (4 of 6) [12/7/2001 5:13:25 PM] If you invert the material side of the reference wall on which the first wall on edge has been created, both walls on edge are relocated (as if you were flipping the geometry): If you invert the material side of the first wall on edge (and not the material side of the reference wall), the second wall on edge is relocated. Indeed, its specification being relative to the first wall on edge, when its input data (i. e. he edge selected on the first wall on edge) is modified, the second wall on edge is rebuilt at a new location. 5. Click OK in the Wall On Edge Definition dialog box. A WallOnEdge. x element is created in the specification tree. A WallOnEdge. x element can be edited: double-click it in the graphic area or in the specification tree to display its creation dialog box and modify the parameters described above, including the edge from which it is created. However, the sketch of a wall on edge cannot be edited directly. Would you need to edit the sketch of a wall on edge, you have to isolate it first. See Isolating Walls. You can cut or copy and paste a wall on edge. If you cut and paste a wall on edge with children elements, these children elements are lost. This may result in update errors. You cannot undo an Isolate action after having modified the wall. Isolating a wall on edge erases all updating data. From an Edge http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0802. htm (5 of 6) [12/7/2001 5:13:25 PM] Extruding This task explains how to create a wall by extrusion. You must have defined the Sheet Metal parameters. A model is available in the Extrude1. CATPart from the samples directory. 1. Click the Extrusion icon . 2. Select a sketch. The Extrusion Definition dialog box is displayed. Several types of extrusion are available: Dimension : the requested input data are a sketch and a dimension, Up to plane or Up to surface: a plane or a surface are input as limit to the extrusion. These functions are used to create walls that are not rectangular. 3. Edit the Length1 and Length2 to set both extremities, for option Dimension. Extruding http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt1100. htm (1 of 4) [12/7/2001 5:13:25 PM] 4. Define the options as needed: Check the option Mirrored extent to extent the material on both sides of the sketch. In that case, only Length1 can be edited. This option is only available if the type is set to Dimension. Extruding http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt1100. htm (2 of 4) [12/7/2001 5:13:25 PM] Push Invert Material Side to invert the direction of the creation of the material. 5. Click OK. The walls corresponding to the selected sketch are created according to the specified options, and added to the specification tree. When the extrusion is the first Sheet Metal feature of the Part, the reference wall is the first wall created based on the first segment of the sketch. For option Up to Surface, while the wall end that is limited by the surface has the shape of the surface, its thickness does not fit the surface. It is a â€Å"rectangular† polygon defined by the first edge that comes into contact with the surface. Extruding http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt1100. htm (3 of 4) [12/7/2001 5:13:25 PM] Check Symmetrical thickness to create thickness inside and outside the sketch. Such an extrusion can also be performed on a sketch made of lines and arcs of circle, provided there are no tangency discontinuities between the different elements. However, in this ase, the Up to plane or Up to surface capabilities are not available, and you cannot isolate such an extrusion. Extrusion walls can be edited and/or isolated. The sketch may not be closed. Extruding http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt1100. htm (4 of 4) [12/7/2001 5:13:25 PM] Isolating Walls This task explains how to isolate a wall. This is possible in two cases: 1. after having created walls by extrusion (see Extruding) 2. after having created a wall on edge (see Creating Walls from an Edge). You must have defined the Sheet Metal parameters. A model is available in the Extrude2. CATPart from the samples directory. Isolating Extruded Walls Right-click the Extrusion. 1 feature and choose the Extrusion. 1 object -; Isolate contextual menu item. 1. The Extrusion Isolate dialog box is displayed. Select one of the wall of the extrusion to be isolated. 2. The selected wall is highlighted in the geometry. This wall is the reference wall, meaning that it can be modified and the other walls will take the modification into account. On the other hand if the other walls are modified the reference wall is an anchoring wall, and modifications will be made around it. The Extrusion Isolate dialog box is updated. 3. Click OK in the dialog box. The walls of the extrusion have been isolated, each with its own sketch. Yet coincidence constraints are automatically generated between the isolated walls. Isolating Walls http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt1701. htm (1 of 4) [12/7/2001 5:13:25 PM] The extrusion’s initial sketch is retained (Sketch. 1 in the example above). Double-click the sketch of the reference wall (here Sketch. 3) and modify it by increasing its length. 4. Exit the Sketcher using the Exit icon . 5. The Part is updated. You can note that the wall that was adjacent to the pad, now lies on it, as it is the reference wall that was modified. Isolating Walls http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt1701. htm (2 of 4) [12/7/2001 5:13:25 PM] However, had you modified the sketch of the wall lying on the pad (Sketch. 4), moving it further away from Wall. 2 as shown here to the right, the updated pad would not take the gap between the walls into account. The resulting part looks like this (Wall. 3 has been modified but still coincides with Wall. 2): Isolating Walls http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt1701. htm (3 of 4) [12/7/2001 5:13:25 PM] You can then edit its sketch if needed. In the present case, the wall on edge had been created with a end. Therefore when isolating this wall from the reference wall, the bend is created as a separate feature that can be edited as well. The angle value between the two walls is displayed for edition. You cannot undo an Isolate action after having modified the wall. Isolating a wall on edge erases all updating data. Isolating Walls http://arbredsy/FmoCXR8 /SheEnglish/sheug. doc/src/sheugbt1701. htm (4 of 4) [12/7/2001 5:13:25 PM] Isolating Walls on Edge Right-click the wall on edge and choose the Wall On Edge contextual menu item. 1. The wall on edge is then changed to a standard wall, as you can see from the specification tree. Creating Rolled Walls This task shows how to create rolled walls (such as pipes, open pipes with flange, etc. ). You must have defined the Sheet Metal parameters, and have a sketch available, in the form of an circular arc. The part is available in the Rolledwall1. CATPart from the samples directory. 1. Click the Extrusion icon . 2. Select the circular sketch. 3. Make sure the type is set to Dimension. Length 1 and Length 2 indicate the location of Limit 1 and Limit 2. 4. 5. Define the options as needed (the length being down to -50 mm): Creating Rolled Walls http://arbredsy/FmoCXR8/SheEnglish/sheug. oc/src/sheugbt1000. htm (1 of 3) [12/7/2001 5:13:26 PM] Check the option Mirrored extent to extend the material on both sides of the sketch. In that case, only Length1 can be edited. Check Symmetrical thickness to create thickness inside and outside the sketch. Push Invert Material Side to invert the direction of the creation of the material. Click OK in the dialog box to create the roll ed wall: 6. Creating Rolled Walls http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt1000. htm (2 of 3) [12/7/2001 5:13:26 PM] The rolled wall is a particular extrusion: he input sketch is either a circular arc or a closed circle, the creation type is always Dimension. The sketch may be open. In that case, you can define where the opening should be. The sketch may be closed. In that case, you have no control on the opening location. The only operations you can combine with a rolled wall in a Sheet Metal model are flanges and cutouts. No other elements (standard wall, bend,†¦ ) are allowed. Creating Rolled Walls http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt1000. htm (3 of 3) [12/7/2001 5:13:26 PM] Creating Bends on Walls This section explains and illustrates different methods to create bends on walls. Bends can only be created between walls, whether manually or automatically, and not between any other Sheet Metal features, such as stamps for example. Create bends from wall: select the two walls, set the bend radius value, the bend extremities, and specify the use of corner relief Generate bends automatically: select the part, then a reference wall Create conical bends: select the part, and choose a reference wall Create flat bends: select a sketch, set the creation mode and limiting option, set the radius and angle in relation to the selected sketch. Creating Bends http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0210. htm [12/7/2001 5:13:26 PM] Manually Creating Bends from Walls This task explains two ways to create bends between walls in the Sheet Metal part. These bends can be created on non-connex walls, and with a constant radius value. Open the BendExtremities01. CATPart document from the samples directory. 1. Select the Bend icon . The Bend Definition dialog box opens. Note that the Radius field is in gray because it is driven by a formula: at that time, you cannot modify the value. Select Wall. 2 and Wall. 5 in the specification tree. The Bend Definition dialog box is updated. 2. Right-click the Radius field: the contextual menu appears. 3. Deactivate the formula: you can now change the value. 4. Enter 4mm for the Radius and click Preview. 5. The bend is previewed, along with its orientation symbolized by arrows. The Left and Right texts further indicate this orientation and are useful to define different bend extremities. Manually Creating Bends from Walls http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0202. htm (1 of 4) [12/7/2001 5:13:27 PM] 6. Click the More button to display further options: You can define: he left and right extremity settings (see also extremities definition settings) the corner relief definition settings and the bend allowance settings. Within the Left Extremity tab, choose the Mini with round relief bend extremity type, deactivate the L1 and L2 length formulas, and set them to 6mm and 3mm respectively. 7. Click the Right Extremity tab, and choose the Curved shape type. 8. Click P review to visualize the left and right extremities. 9. Click OK in the Bend Definition dialog box. 10. The Bend is created with the specified extremity types. Manually Creating Bends from Walls ttp://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0202. htm (2 of 4) [12/7/2001 5:13:27 PM] The extremities and the corner relief defined with the current dialog box will apply locally and prevail over any other global definition. Be careful when creating bends with square or round relief. Depending on the geometry configuration, this can lead to removing more matter than you would expect. Indeed, a corner relief being computed on the whole intersection of the elements involved (bends or bend/wall), in the following configuration the matter is removed till the end of the wall. Bend with no relief Bend with square relief In this case, it is best to replace the bend corner relieves with cutouts (identified in red in the figure below) that will act as corner relieves removing matter to the part. Manually Creating Bends from Walls http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0202. htm (3 of 4) [12/7/2001 5:13:27 PM] Generating Bends Automatically This task explains how to automatically generate bends between walls in the Sheet Metal part. You can first create all the bends, then modify the parameters for any of the generated bends. However, when an ambiguity arises, that is when more than two bends end on the same vertex, the bends are not automatically generated. You then need to create them manually, so as to explicitly select the walls between which the bends are to be created. Open the BendExtremities01. CATPart document from the samples directory. 1. Select the Automatic Bends icon . The bends are created. Generating Bends Automatically http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0206. htm (1 of 4) [12/7/2001 5:13:27 PM] Double-click the bend of interest: Bend. 4 The Bend Definition dialog box opens. 2. Right-click the Radius field: the contextual enu appears. 3. Deactivate the formula: you can now change the value. 4. Enter 4mm for the Radius and click Preview. 5. Bend. 4 is modified. 6. Click the More button to display further options: You can re-define: the left and right extremity settings (see also extremities definition settings) the corner relief definition settings and the bend allowan ce settings. Generating Bends Automatically http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0206. htm (2 of 4) [12/7/2001 5:13:27 PM] Within the Left Extremity tab, choose the Mini with round relief bend extremity type, deactivate the L1 and L2 length formulas, and set them o 6mm and 3mm respectively. 7. Click the Right Extremity tab, and choose the Curved shape type. 8. 9. Click OK in the Bend Definition dialog box. The bend is modified with the specified options The extremities and the corner relief defined with the current dialog box will apply locally and prevail over any other global definition. Push the more button to display; the extremities definition settings and the corner relief definition settings and the bend allowance settings. Generating Bends Automatically http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0206. htm (3 of 4) [12/7/2001 5:13:27 PM] Creating Conical Bends This task explains how to generate conical bends between two walls in the Sheet Metal part. These bends are different from the standard bend in that they allow different radius values at each end of the bend. Open the ConicalBend1. CATPart document from the samples directory. Select the Conic Bend icon . The Conic Bend Definition dialog box opens. 1. Select Wall. 1 and Wall. 2 in the specification tree or in the geometry. The Bend Definition dialog box is updated, and arrows are displayed indicating the walls orientation. 2. You can click on the arrow to invert them if needed. The LIM1 and LIM2 texts indicate the endpoints for the bend. Enter the radius values for each end of the conical bend. If the difference between the specified radius values does not allow the generation of a cone with an angle greater than 1 degree, a warning is issued prompting you to increase one of the radii. Click OK in the Warning dialog box, and increase/decrease the radius values. 3. Conical Bends http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0204. htm (1 of 3) [12/7/2001 5:13:27 PM] By default, Radius 2 is twice Radius 1. 4. Click More†¦ to display further options. 5. Choose the bend extremities: Mini with no relief: the shortest possible bend is created, and presents no relief Curve shaped: the bend is created keeping the tangency continuity with the support walls. Maximum: the bend is calculated between the furthest opposite edges of the supporting walls. 6. Click OK. The Bend is created. The two walls must be connected by the edge of their internal faces. The Angle field is locked. It indicates the angle value between the two walls between which the bend is computed. Conical Bends http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0204. htm (2 of 3) [12/7/2001 5:13:27 PM] Should you choose the Curve shaped extremity option, the bend would look like this: Conical Bends http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0204. htm (3 of 3) [12/7/2001 5:13:27 PM] Creating Bends From a Line This task explains how to generate bends based on a line (also called flat bends) in the Sheet Metal part. A wall and a bend are created. Open the FlatBend1. CATPart document from the samples directory. Select the reference wall then the Bend From Flat icon . 1. The Bend From Flat Definition dialog box opens. Select a sketch (Sketch. 3 here). This sketch must necessarily be a line. 2. 3. You can choose the line extrapolation option: he line is extrapolated up to the wall edge (Bend From Flat Until) the line is not extrapolated, and the bend is limited to the line’s length (Bend From Flat Length) Set the bend radius value. You may need to deactivate the formula using the Formula -; Deactivate contextual menu on the Radius field. 4. 5. Set the angle value between the generated wall and the reference wall. 6. Click OK to create the bend. Bend s From Line http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0205. htm (1 of 2) [12/7/2001 5:13:28 PM] When creating such a bend on a reference wall (first wall), an arrow indicates which part is to be folded. Click this arrow to invert the side that will be bent. Such bends cannot be created, if the section to be folded already intersects the part. Bends from line should be performed on end walls, or prior to creating further walls on the bent one. Perform the bend before creating the stamping features, as stamps are not retained when the part is folded with the bend. Bends From Line http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0205. htm (2 of 2) [12/7/2001 5:13:28 PM] Creating Swept Walls This section explains and illustrates how to create and use various kinds of swept walls, i. e. alls based on a given contour that is swept along a spine. Create a flange: select a spine, and set the radius, length, and angle values. Create a hem: select a spine, and set the radius, and length values. Create a tear drop: select a spine, and set the radius, and length values. Create a swept flange: select a spine, and a user-defined profile Redefine swept walls limits: choose the Relimited ty pe, and select a point lying on the spine or a plane normal to the spine and intersecting it as limits Display swept walls axes in drafting sheets: open a CATDrawing document, click the Unfolded View icon, and select a plane Selecting the Spine Whatever the type of the swept wall you wish to create, you first need to select one or more contiguous edges to make up the spine along which the contour, either pre- or user-defined, is to be swept. You can: manually select one, or more, edge(s) Selection without propagation Resulting flange without propagation select one edge and click the Tangency Propagation button: all contiguous and tangent edges are selected. In this case, would you need to remove one edge, you need to manually select it. Remember that only extremity edges can be removed without breaking the continuity between edges. Creating Swept Walls http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0600. htm (1 of 2) [12/7/2001 5:13:28 PM] Selection with propagation Resulting flange with propagation Creating Swept Walls http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0600. htm (2 of 2) [12/7/2001 5:13:28 PM] Creating a Flange This task explains how to generate a flange from a spine and a profile. Open the SweptWall01. CATPart document from the samples directory. 1. Select the Flange icon . The Flange Definition dialog box opens. 2. Select the edge as shown in red. Creating a Flange http://arbredsy/FmoCXR8/SheEnglish/sheug. oc/src/sheugbt0601. htm (1 of 3) [12/7/2001 5:13:28 PM] Enter 2mm in the Radius field, 10mm in the Length field and 120 ° for the Angle. 3. Click the More button to display the Bend Allowance tab allowing you to locally redefine the bend allowance settings. You may need to deactivate the formula using the contextual menu on the field and choosing Formula -; Deactivate bef ore editing the value. 4. In this case, the new K Factor value overrides the value set in the Sheet Metal Parameters. 5. Click OK to create the flange. Creating a Flange http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0601. tm (2 of 3) [12/7/2001 5:13:28 PM] The feature is added to the specification tree. Use the Tangency Propagation button to select all tangentially contiguous edges forming the spine (see Selecting the Spine). You can redefine the flange limits by choosing the Relimited option (see Redefining Swept Walls Limits). Creating a Flange http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0601. htm (3 of 3) [12/7/2001 5:13:28 PM] Creating a Hem This task explains how to generate a hem from a spine and a profile. The SweptWall01. CATPart document is still open from the previous task. If not, open the SweptWall02. CATPart document from the samples directory. Select the Hem icon in the Swept Walls sub-toolbar. 1. The Hem Definition dialog box opens. 2. Select the edges as shown in red. Creating a Hem http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0602. htm (1 of 3) [12/7/2001 5:13:29 PM] Enter 2mm in the Radius field, and 3mm in the Length field. 3. Click the More button to display the Bend Allowance tab allowing you to locally redefine the bend allowance settings. You may need to deactivate the formula using the contextual menu on the field and choosing Formula -; Deactivate before editing the value. 4. In this case, the new K Factor value overrides the value set in the Sheet Metal Parameters. 5. Click OK to create the hem. Creating a Hem http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0602. htm (2 of 3) [12/7/2001 5:13:29 PM] The feature is added to the specification tree. Use the Tangency Propagation button to select all tangentially contiguous edges forming the spine (see Selecting the Spine). You can redefine the hem limits by choosing the Relimited option (see Redefining Swept Walls Limits). Creating a Hem http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0602. htm (3 of 3) [12/7/2001 5:13:29 PM] Creating a Tear Drop This task explains how to generate a tear drop from a spine and a profile. The SweptWall01. CATPart document is still open from the previous task. If not, open the SweptWall03. CATPart document from the samples directory. Select the Tear Drop icon in the Swept Walls sub-toolbar. 1. The Tear Drop Definition dialog box opens. 2. Select the edge as shown in red. Creating a Tear Drop http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0603. htm (1 of 3) [12/7/2001 5:13:29 PM] Enter 3mm in the Radius field, and 8mm in the Length field. 3. Click the More button to display the Bend Allowance tab allowing you to ocally redefine the bend allowance settings. You may need to deactivate the formula using the contextual menu on the field and choosing Formula -; Deactivate before editing the value. 4. In this case, the new K Factor value overrides the value set in the Sheet Metal Parameters. 5. Click OK to create the tear drop. Creating a Tear Drop http://arbredsy/FmoCXR8/SheEnglish/sheug. do c/src/sheugbt0603. htm (2 of 3) [12/7/2001 5:13:29 PM] The feature is added to the specification tree. Use the Tangency Propagation button to select all tangentially contiguous edges forming the spine (see Selecting the Spine). You can redefine the tear drop limits by choosing the Relimited option (see Redefining Swept Walls Limits). Creating a Tear Drop http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0603. htm (3 of 3) [12/7/2001 5:13:29 PM] Creating a Swept Flange This task explains how to generate a swept flange from a spine and a user-defined profile. The SweptWall01. CATPart document is still open from the previous task. If not, open the SweptWall04. CATPart document from the samples directory. 1. Using the Sketcher , define a profile in the yz plane as shown below: Then quit the Sketcher, using the Exit icon Select the Swept Flange icon in the Swept Walls sub-toolbar. 2. The User Defined Flange Definition dialog box opens. 3. Select the edge and the profile, as shown in red. Creating a Swept Flange http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0604. htm (1 of 3) [12/7/2001 5:13:29 PM] The dialog box looks like this: Click the More button to display the Bend Allowance tab allowing you to locally redefine the bend allowance settings. You may need to deactivate the formula using the contextual menu on the field and choosing Formula -; Deactivate before editing the value. 4. In this case, the new K Factor value overrides the value set in the Sheet Metal Parameters. 5. Click OK to create the swept flange. Creating a Swept Flange http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0604. htm (2 of 3) [12/7/2001 5:13:29 PM] The feature is added in the specification tree. Use the Tangency Propagation button to select all tangentially contiguous edges forming the spine (see Selecting the Spine). You can redefine the tear drop limits by choosing the Relimited option (see Redefining Swept Walls Limits). Creating a Swept Flange http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0604. tm (3 of 3) [12/7/2001 5:13:29 PM] Redefining Swept Wall Limits This task explains how to redefine the spine’s limits when creating any type of swept walls, using existing geometric elements: points lying on the spine or intersecting planes.. Open the SweptWall01. CATPart document. 1. Select the Flange icon . The Flange Definition dialog box opens. Using the combo l ist, choose the Relimited type. 2. The Flange Definition dialog box is updated and now displays two Limit fields. Select the spine. Here we select a single edge. See also Selecting the Spine. 3. Redefining Swept Walls Limits http://arbredsy/FmoCXR8/SheEnglish/sheug. oc/src/sheugbt0606. htm (1 of 2) [12/7/2001 5:13:30 PM] Successively select the two limiting elements. Here we select a point lying on the spine as the first selecting element, and a plane intersecting the spine as the second limiting element. 4. Make sure intersecting elements are normal to the spine, and they intersect it only once. Specify the swept wall values. In the example of the flange you set the Radius, Length and Angle values. You may also click More to display further options. See Creating a Flange. 5. 6. Click OK. The swept wall is created within the limits on the spine. Redefining Swept Walls Limits ttp://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0606. htm (2 of 2) [12/7/2001 5:13:30 PM] Displaying Swept Wall Axes This task explains how to generate an unfolded view of a part with swept wall in a drawing sheet including the axes of planar hems, tear drops, and flanges are displayed within the drawing. The SweptWall01. CATPart document is still open from the previous task. If not, open the SweptWall05. CATPart document from the samples directory. Make sure that the Generate axis button is checked in the Tools - Options - Mechanical Design - Drafting - Generation tab, prior to generating a view in a . CATDrawing document. 1. Click or select File - New†¦ 2. Select the Drawing type and click OK. 3. Click OK. For more information about this workbench, refer to Generative Drafting User’s Guide. Displaying Swept Walls Axes http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0605. htm (1 of 2) [12/7/2001 5:13:30 PM] 4. The drawing sheet appears. Tile the windows horizontally using the Window -; Tile Horizontally menu item. 5. Select the Unfolded View icon in the Projections toolbar from Generative Drafting Workbench. 6. This icon is added to the Projections toolbar provided the Sheet Metal workbench is present. Choose the xy plane in the Sheet Metal specification tree. The unfolded view is displayed with the planar swept wall axes. 7. Displaying Swept Walls Axes http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt0605. htm (2 of 2) [12/7/2001 5:13:30 PM] Unfolding Unfolded Sheet Metal parts can be displayed in two ways: Folded/Unfolded View Access Concurrent Access Each Sheet Metal feature is created in a given view: folded, or unfolded. Editing a feature must be done in its definition view. If not, a message is automatically issued, prompting you to change views, before editing the feature. Unfolding http://arbredsy/FmoCXR8/SheEnglish/sheug. oc/src/sheugbt1200. htm [12/7/2001 5:13:30 PM] Folded/Unfolded View Access This task shows how to unfold the part. 1. Click the Unfold icon . The part is unfolded according to the reference wall plane, as shown below. 2. Click this icon again to refold the part for the next task. Bend limits and stamping are now displayed in the unfolded view. Whe n designing in context, If a CATProduct document contains several SheetMetal parts, only one part can be visualized in the unfolded view at a time. Folded/Unfolded View Access http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt1201. htm [12/7/2001 5:13:30 PM] Concurrent Access This task explains how to display the Sheet Metal part in two windows: one with the folded view, one with the unfolded view. Any modification in one window is displayed in the other window. 1. Click the Multi-view icon . The part is unfolded in a second window. 2. Choose the Window -; Tile Horizontally menu item. Both windows are tiled. Activate the window in which you want to work. Concurrent Access http://arbredsy/FmoCXR8/SheEnglish/sheug. doc/src/sheugbt1202. htm (1 of 2) [12/7/2001 5:13:30 PM] Any modification in one view is taken into account in the other view enabling the user to make modifications in the best possible context. In the multi-view mode as in the standard unfolded view, all constraints are displayed in the geometrical views. Once in the Multi-view mode, the standard icon Unfold is not longer available. The Multi-view function is not available from a standard unfolded view. Only parts with bends can be unfolded. Cutting faces and open faces are not displayed in Multi-view mode. Concurrent Access How to cite Sheet Metal Design Site Map, Papers