基于曲面逼近的包容式节点NURBS曲面建模方法

Bugle formed joint NURBS surface modeling method based on surface approximation

包容式节点是一种新型管状相贯式节点。文中针对于包容式节点建模问题提出了一种新的建模方法。该方法首先给出了一种由形状参数驱动的初始参数模型,用于近似描述包容式节点。之后通过LSPIA算法,采用修正控制点的方式,将该模型按照一定精度离散后通过迭代逼近的方式重构为NURBS曲面模型。该方法可以通过形状参数的设计快速调整或建立包容式节点的基本曲面形状,从而达到较好的进行正向表达的目的,并在此基础上根据需要设置控制点数目,获取对应的包容式节点NURBS初始曲面模型。

The bugle formed joint is a new type of tubular intersecting joint.In this article,a modeling method for bugle formed joints is proposed.Firstly,an initial parameter model driven by shape parameters is given to approximately describe the bugle formed joint.Then,by means of the LSPIA algorithm,the model is reconstructed into the NURBS surface model by iterative approximation after discretization with certain accuracy by modifying the control points.Thanks to this method,the basic surface shape of the bugle formed joint can be quickly adjusted or set up with the help of the design of shape parameters,so as to achieve better forward expression.On this basis,the number of the control points can be set according to the actual needs,in order to work out the bugle formed joint NURBS initial surface model.