Abstract: Based on the thermal-elastic-plastic FEM theory, a three-dimensional numerical model is set up for studying the welding residual stresses in the thick titanium plate by electron beam welding. The computation results show that there exist the very complex residual stresses in the EBW thick plate joint, and there is the transverse residual compression stress at the area near the weld on the surface, which is useful for the structure strength. But the residual stress value in the welded joint is generally more than that on the surface, especially there is three-dimensional and large residual tensile stress at the region near to the upper surface. The residual stress measurements verify the conclusion.

Key words: Residual stress, EBW, FEM, Temperature field, Titanuim alloy