Development And Application Of Large Scale General Visualization System For Finite Element Based On SiPESC Platform

The finite element visualization system is an important part of finite element analysis system.It converts the large-scale and complicated computing data to graphics through the computer graphics technology,so users can understand computing data visually and deeply.With the developing of finite element method and computer graphics,the finite element data structure becomes increasingly complicated and new visualization methods continue to appear.In order to apply new visualization methods to complicated finite element data,the research on finite element visualization system with high scalability is very critical.Meanwhile,the computing power of desktop computer has been improved greatly with multicore parallel and GPU computing techniques,so the finite element model scale from tens of thousands or hundreds of thousands of nodes in past to over millions of or tens of millions of nodes.Therefore,the research on large-scale finite element visualization is of great significance.Base on the background above,this dissertation aims at investigating scalable system architecture for large scale general finite element visualization system,large-scale visualization strategies,general visualization methods and customized system.The main research contents are as follows:Firstly,a scalable system architecture for constantly evolving system requirement of finite element visualization is presented.On the design of the core architecture of the system,using plug-in technology and according to the finite element data processing flow,the visualization system is divided into multiple independent modules.So each module can be replaced dynamically.On the converting finite element data to graphics data,by the employment of stream architecture,the large-scale data can be processed efficiently,and new visualization method can be added dynamically.On the implementation of each module,a unified extension mechanism which based on multiple design pattern is presented.So almost all parts of the visualization system(i.e.,data file type,element type,result type and visualization methods)can be extended in the same way.Secondly,an effective strategy for large-scale finite element models is presented.In this strategy,a parallel model simplification method based on the topological connection is developed through the analysis of finite element meshes.This method removes all internal faces in meshes,so the graphics data can be reduced greatly.Furthermore,by the employment of GPU acceleration technology,which can save graphics data in GPU memory directly,the graphics rendering capabilities can be improved efficiently.In addition,the element-hiding and cut-surface methods are implemented to observe the interior of the meshes.So the shortcomings caused by displaying the surface only can be remedied.Using this strategy,the visualization system implements high-performance display for large-scale finite element models with tens of millions of nodes on desktop computers.In comparison to several commercial and open-source visualization software,the feasibility of the presented strategy is demonstrated.Thirdly,an available solution for lightweight visualization of finite element results during product development is presented.In this solution,all kinds of finite element result files can be imported through the unified extension mechanism.Then the model file size can be reduced greatly by mesh simplification and result selection.Finally,the simplified data are stored in two widely used format,so users can visualize the file easily.Numerical results show that the finite element result files are small enough to satisfy lightweight visualization after simplification.Finally,some extensions and applications are achieved based on the new finite element visualization system.In general visualization methods,using the unified extension mechanism,many methods are implemented,which contain the cloud chart and deformation for finite element results,model management method and model partition method for multi-level substructure,line element shape visualization and connection visualization of line element and volume element.The implementation of these methods further validates the scalability of the visualization system.In customization,the structural topology optimization result visualization is implemented based on element hiding method,model updating visualization is developed based on model management method and wet vibration modes visualization is achieved based on filter module.The generality of the finite element visualization system is showed through these applications.