Algorithm for mixed meshing multiple trimmed parametric surfaces for finite element analysis 多個(gè)裁剪參數(shù)曲面的有限元混合網(wǎng)格剖分法
Using the above algorithms , this thesis proposes two efficient algorithms for evaluating parametric surfaces 根據(jù)以上算法,本文提出了對(duì)參數(shù)曲面快速求值的兩種新方法
The former method is parametric surface integral and the latter is to triangulate closed surface based on nurbs . ( 4 ) the key technique in probabilistic damaged stability calculation is discussed ( 4 )對(duì)概率破艙穩(wěn)性計(jì)算中多艙組合破損時(shí)船體的浮態(tài)與穩(wěn)性計(jì)算發(fā)生異常的原因進(jìn)行了研究。
The problems on parameterization of implicit algebraic surfaces and inversion of parametric surfaces are discussed and the inversion equations for some nurbs surfaces are derived in detail 探討隱式曲面參數(shù)化及cad超曲面重構(gòu)技術(shù)研究及其應(yīng)用參數(shù)曲面反演問題,具體導(dǎo)出了一些nurbs曲面的反演方程。
Secondly , based on nurbs curves approximation algorithm , a nurbs surface approximation algorithm on discrete data sets is given . thirdly , a shape - preserving parametric surface interpolation to data set is given 2基于所給的nurbs曲線的逼近算法,建立了帶插值條件的離散點(diǎn)集的nurbs曲面的逼近算法。
( 1 ) presents a grid - based intersection algorithm of parametric surface and plane , which is characterized by effectiveness and conciseness , and has been successfully implemented in the rp data processing software 所作的主要工作如下: ( 1 )提出一種基于網(wǎng)格劃分的參數(shù)曲面與平面求交算法。這種算法簡(jiǎn)單、實(shí)用,已成功地應(yīng)用于基于cad模型直接分層的rp數(shù)據(jù)處理軟件中。
According to topological structure of control mesh , we generate generalized rational parametric surfaces in two manners . for a control mesh with consistent parameterization , the surface can be easily constructed because it can be mapped to differential manifold directly 對(duì)于具有簡(jiǎn)單拓?fù)浣Y(jié)構(gòu),存在著一致的全局參數(shù)化的控制網(wǎng)格,我們將把控制網(wǎng)格直接映射到微分流形上,因此可以很容易地對(duì)曲面進(jìn)行構(gòu)造和控制。
Its properties and design method is discussed in chapter 4 . for control meshes with arbitrary topology , we present a universal method in chapter 5 to construct parametric curves and surfaces . generalized rational parametric surface can be controlled precisely and flexible , and it is easy to model local features and 3d primitives 然后,在第五章中,我們將控制網(wǎng)格進(jìn)一步推廣到任意可定向二維拓?fù)淞餍危岢隽艘粋€(gè)通用的方法將控制網(wǎng)格映射到與之拓?fù)渫叩奈⒎至餍紊?,統(tǒng)一了廣義有理參數(shù)曲線曲面的構(gòu)造過程。