Research And Software Development On Finite Non-Manifold Geometric Modeling System

This paper presents a new boundary representation oriented grid generation system. This representation which is called finite non-manifold geometric modeling system(FNGM system)is based on the radial edge structure model and partial entities structure model.The representation improves the efficiency of adjacency relationships of topological entities, the storage complexity and the time efficiency. And the improvements meet the requirements of the grid generation system, which includes mesh pre-treatment, mesh post-treatment, and numerical analysis.With the consideration of the characteristics of the grid generation system, the representation simplifies the non-manifold model, and discards some redundant topological relationships consisting of acnode, isolated edge and isolated face .This paper defines the description non-manifold domain, topological structure and data structure exactly.The detailed definitions of 13 elements in data structure of finite non-manifold modeling are given in this paper. Based on their functions, those elements are classified into geometric layer, modeling layer, concept layers, and geometric attribute layer.This Paper describes a software module which is set up based on finite non-manifold geometric modeling system. This module establishes some basic functions such as model's definitions of topological relations, geometric description information, the operations of the construction and deconstruction and etc.