Research Of Post-processing Technologies In Finite Element Simulations Of Welding Process

As the welding technology progressing and the aviation and aerospace industry developing, newmaterials, new structures and new technology in welding emerge constantly. As a result, the problemsof welding quality are becoming more and more complex. A low-cost, but high-efficiency solution isprovided by the finite element simulation of welding process to predict the properties of weldingjoints and optimize the welding process. Currently, the finite element models of welding become moreand more complex, and the calculated data files are more and more discrete. Post-processing analysisof such data files have become an urgent work to finish. Based on WeldTPS and some commercialfinite element software, a research on post-processing technology of finite element simulations inwelding process was carried out.Different data formats in different output files were analyzed. And corresponding programs weredesigned to extract respective data. Via the method of stress smoothing in every element, the weldingstress at the Gaussian integration point in the output files were converted to the results of nodes, andthen adopted in the post-processing system to display in the form of visual graphics. In order to sharethe different format data and use in the follow-up analysis, the extracted data were stored in a uniformformat.A surface-searching algorithm and redundant-Line-filtering algorithm were designed afteranalyzing the topological relations of hexahedral elements of eight-node. The finite element models ofwelding components were rebuilt with OpenGL. Based on the computer graphics, translating, scalingand rotating of models were realized to observe and analyze the results thoroughly.In the modular of post-processing, curves of temperature-time and stress–time were fitted inorder to display the course of all the welding field variables. The valid-region-searching algorithmwas optimized, and contours were generated easily. The color rendering model and the region fillfilters were designed to present the nephograms of temperature, stress, displacement and welding poolon the surface and section of entities. Nodal displacements caused by welding were scaled up and thenadded to the original model. And then the deformation would be presented comparing with originalmodel.The algorithms mentioned above were encapsulated and a post-processing system of finiteelement simulation of welding process was developed. The output files of WeldTPS and somecommercial finite element software about some typical welding process were imported to the post-processing system and analyzed. The results showed that the system can meet the basic needs todeal with data of welding temperature, stress and displacement field.