本文選題：魯棒性 + 直接建模��； 參考：《浙江大學(xué)》2017年碩士論文

【摘要】：參數(shù)化特征建模是目前主流的CAD建模方法,但是隨著現(xiàn)在的模型越來越復(fù)雜,對參數(shù)化特征模型進行變動修改的效率和健壯性變得越來越低,而且基于歷史的建模方式限制了用戶在進行模型變動修改時的靈活性。與參數(shù)化特征建模不同,直接建�？梢詫c、邊、面直接進行操作,其建模過程與歷史無關(guān),特別是直接建模在進行復(fù)雜模型變動修改時具有高效、靈活的特點,因此直接建模技術(shù)越來越受到重視。鑒于目前的直接建模技術(shù)還存在不足之處,本文針對現(xiàn)有方法所存在的問題,研究健壯高效的直接建模算法。本文主要開展的工作包括:(1)提出基于B-rep直接修改的直接建模算法。該算法通過對B-rep直接進行簡單的幾何拓撲修改操作而不采用復(fù)雜耗時的布爾運算實現(xiàn)直接建模功能,不僅比現(xiàn)有方法更加魯棒,而且更加高效。(2)提出基于拓撲圖的過渡特征組生成/抑制順序確定算法。該算法通過充分利用過渡面之間的拓撲上下文,得到更加合理的過渡特征生成/抑制順序。(3)提出能夠有效處理自由曲面的直接建模算法。該算法通過合理拓展自由曲面以及有效構(gòu)建延展自由曲面和目標操作自由曲面,使得算法能夠處理帶有自由曲面的復(fù)雜模型。最后,在本文工作的基礎(chǔ)上,設(shè)計并實現(xiàn)一個直接建模原型系統(tǒng),通過實例測試驗證了本文所提出算法的有效性。
[Abstract]:Parameterized feature modeling is the mainstream CAD modeling method at present, but with the increasing complexity of the present model, the efficiency and robustness of modifying the parameterized feature model become lower and lower. Moreover, the historical modeling method limits the flexibility of the user when making model changes. Different from parameterized feature modeling, direct modeling can operate directly on points, edges and surfaces, and its modeling process has nothing to do with history. Especially, direct modeling has the characteristics of high efficiency and flexibility in changing and modifying complex models. Therefore, more and more attention has been paid to direct modeling technology. In view of the shortcomings of the current direct modeling techniques, this paper studies a robust and efficient direct modeling algorithm in view of the problems existing in the existing methods. The main work of this paper is to propose a direct modeling algorithm based on B-rep. This algorithm implements the direct modeling function by directly modifying B-rep geometry and topology without using complex and time-consuming Boolean operations, which is not only more robust than the existing methods. Furthermore, a new transition feature group generation / suppression order determination algorithm based on topology graph is proposed. By making full use of the topological context between the transition surfaces, the algorithm obtains a more reasonable transition feature generation / suppression order. 3) A direct modeling algorithm which can effectively deal with free surface is proposed. By extending the free surface reasonably and effectively constructing the extended free surface and the target operating free surface, the algorithm can deal with the complex model with the free surface. Finally, a direct modeling prototype system is designed and implemented on the basis of the work in this paper. The effectiveness of the proposed algorithm is verified by an example.
【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TP391.7

【參考文獻】

相關(guān)碩士學(xué)位論文 前1條

1 秦孝廉;直接編輯后的特征模型自動更新[D];浙江大學(xué);2016年

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本文編號：2041124