Research Of Visualization System In The Preprocessing Stage Of Welding Simulation Based On Large Structure

Though traditional welding process is proved to be more mature, for complex welding joint or large structures, trying experiments to test the welding quality will not only delay the project progress, but also improve the manufacturing cost and is not conducive to optimize the best welding method effectively. On the contrary, with the help of computer, welding simulation will decrease the cost of process design and shorten the manufacturing cycle. However, it's difficult to set parameter in the process of welding simulation. If the parameter can be set visually, the pretreatment process will be simplified.This paper is dedicated to develop the pre-processing visualization system of welding simulation,which is applied to large structure. The main research content and the implementation results are as follows:System development framework is built with the aid of MFC foundation classes,and OpenGL visual pipeline is laid based on computer graphics principle.Besides,this article adopts the idea of object-oriented concept to design welding simulation pretreatment visualization system.According to the actual demand in the process of welding, object models related to welding are constructed(welding materials, welding heat source, welding path, fixture, boundary conditions, etc.), and it's necessary to establish the coupling relationship between each model object,so as to explain the actual welding process.In order to make the visualization system effective in the pre-processing of welding simulation,there should be revelant techniques and Algorithms.The key technology and algorithms used in this system are surface grid rendering algorithm( " hollowing out "), intelligent recognition technology based on the geometric topology, geometry intersection algorithm about fixture and constraint surface, weld definition technology in the measure of visualization,and unit set extraction algorithm used in surface boundary condition definition.The System uses the grid artifact as a test case,whose grid number is 432801(400×200×216). The visualization system can be put into use in several aspects,such as file read, interactivity, visualization, cutting, file storage, computing links and so on. It realizes the visualization of grid file, basic interaction, the definition of welding materials, the definition of welding heat source, the visual definition about welding path, fixture setting, the definition of varieties of boundary conditions, cutting and other auxiliary functions.As a result,the ideal simulation effect and application result is obtained.Traditional welding procedures and process measures can be simulated in the form of digital, with the help of related parameters definition in the pre-processing visualization system, cooperating with calculation module and a third-party post-processing software in welding simulation, so as to realize the approximation of the actual working condition of welding welding process, reduce the production cost, and improve the efficiency of the process optimization.