Development and application of the adaptive mesh technique in the three-dimensional numerical simulation of the welding process

The adaptive mesh technique is developed and applied in the three-dimensional numerical simulation of the welding process on the basis of commercial software. A special user subroutine is worked out to accomplish this function. This technique can make a dense mesh moving simultaneously with the heat source, while the other area of the structure has a much coarser mesh, greatly reducing the number of nodes and elements in the analysis. The temperature field, and the displacement and stress distributions during the welding process are analyzed by the FEM method with an adaptive mesh and the analysis is also conducted with the normal FEM method. The temperature field, and the displacement and stress distributions obtained with each method are compared. The results show that the temperature fields and the displacement distributions of simulation with an adaptive mesh correspond very well with those for without an adaptive mesh. Although the stress distributions have some difference, the trends of the stress distribution correspond. The comparison of the computing time of the two meshes indicates that the adaptive mesh can greatly reduce the calculation time when used for the welding process.