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良好的基礎。參考文獻[1] [M].北京:清華大學出版社,2001[2] [M].北京:機械工業(yè)出版社,2000[3] [M].沈陽:東北大學出版社 2003[4] [M].上海:上??茖W技術出版社 2003[5] [M].,1997[6] [M].:人民交通出版社,2001[7] 清華大學 [M].:機械工業(yè)出版社,1998[8] 鐘建國 廖耘 [M].長沙:中南大學出版社,2002[9] 肖盛云 [M].重慶:重慶大學出版社,1997[10] 梁治明. 材料力學[M]. 遼寧:高等教育出版社出版,1985.[11] The Motor Vehicle Newton Steeda,Garrett,1962[12] 陳家瑞 汽車構造(下冊) 第2版 機械工業(yè)出版社 2000.(08)[13] Bostwick C C,Szadkowski Vibrations DuringEngagements of Dry Friction Clutches[R].SAE Technical Paper,982846:689~701 [14] Adolf Goetzberger, Christopher materials,past,present,future. Solar Energy Materialsamp。Solar Cells,62(2000):119[15] , of SolarGradesilicon refining Intermetallics,2003(11):11111117附 錄我們提出了一種新的手段,能使自由行態(tài)的曲面造型相互影響。這種造型方法提供給用戶們的是一種無限的,柔順的,沒有固定控制的曲面,從而取代了那種固定的網(wǎng)狀控制點。用戶們自由地實施那些經(jīng)過處理的適合操作指令的控制點和曲線。這些復雜的曲面形狀也許會因為增加更多的控制點和曲面而變得沒有明顯的界限。在利用那些控制的約束,這些曲面的形狀會在一種或多種的簡單的標準下而變得十分確定,就比如光滑度。我們解決導致強迫變形的最優(yōu)化問題的方法停留在一個允許不一致的B型活動曲線規(guī)曲面細分曲面描寫上。自動細分是用來確保那些約束是滿足要求,而不去執(zhí)行錯誤的領域。高效的數(shù)字化表示會在公式和描述問題上的線性開發(fā)中獲得。相互影響的自由形態(tài)曲面設計的最基本目標是能使用戶能簡單的控制曲面的形狀。一般來說,這個目標的追尋已經(jīng)由一種尋找“正確”的曲面描述所構成,對于用戶來說,他們的自由程度是足以控制指揮操作的。處理曲面造型的要素,是用控制操作B型活動曲線規(guī)的嚙合或其他曲面制作的張力,清楚得地反映這種看法。這種控制嚙合處理出現(xiàn)在大型的測量上,因為曲面控制點轉(zhuǎn)移的響應是直觀的:拉或推一個控制點會造成那些本來能輕易地通過良好的相互影響位置的確定來控制的形狀,發(fā)生一個局部撞擊或凹陷。不幸的是,那些局部撞擊或凹陷不會只對想創(chuàng)作的人起重要作用。舉例來說,盡管幾乎任何用控制嚙合面方法的人都有試著去做一個概念化的簡單變化的失敗經(jīng)驗,但是最后他們強迫去精確地復位許多甚至是全部圖形,通過控制點去實現(xiàn)所希望的外形。這種我們將在紙上描述的工作表明了一個通過切斷控制與描述之間聯(lián)系來避開不可彎曲性的能力。我們想象著提供給用戶的造型是一塊無限的柔性片狀光滑曲面它本身沒有固定的控制或構造,按它的復雜性和能力性決定細節(jié)方面也沒有前端限制。對這塊曲面來說,用戶也許能很自由地附加一種特征變化,就像那些為了處理知道相互影響的曲面操作而年切斷的點和彎曲曲線。附錄 外文文獻Variational Surface modelingWe present a new approach to interactive modeling of freefrom surfaces. Instead of a fixed mesh of control points, the model presented to the user is that of an infinitely malleable surface, with no fixed controls. The user is free to apply control points and curves which are then available as handles for direct manipulation. The plexity of the surface’s shape may be increased by adding more control points and curves, without apparent limit. Within the constraints imposed by the controls, the shape of the surface is fully determined by one or more simple criteria, such as smoothness. Our method for solving the resulting constrained variational optimization problem rests on surface representation scheme allowing nonuniform subdivision of Bspline surfaces. Automatic subdivision is used to ensure that constraints are met, and to enforce error bounds. Efficient numerical solutions are obtained by exploiting linearities in the problem formulation and the representation. The most basic goal for interactive freeform surface design is to make it easy for the user to control the shape of the surface. Traditionally, the pursuit of this goal has taken the form of a search for the “right” surface representation, one whose degrees of freedom suffice as controls for direct manipulation by the user. The dominant approach to surface modeling, using a control mesh to manipulate a Bspline or other tensor product surface, clearly reflects this outlook.The control mesh approach is appealing in large measure because the surface’s response to control point displacements is intuitive: pulling or pushing a control point makes a local bump or dent whose shape is quite easily controlled by fine interactive positioning. Unfortunately, local bumps and dents are not the only features one wants to create. For example, almost anyone who has used a control mesh interface has had the frustrating experience of trying to make a conceptually simple change, but being forced in the end to precisely reposition many—even all—the control points to achieve the desired effect.The work we will describe in this paper represents an effort to escape this kind of inflexibility by severing the tie between the controls and the representation. The model we envision presenting to the user is that of an infinitely malleable piecewise smooth surface, with no fixed controls or structure of its own, and with no prior limit on its plexity or ability to resolve detail. To this surface, the user may freely attach a variety of features, such as points and flexible curves, which then serve as handles for direct interactive manipulation of