Abstract: The 3D welding numerical simulations of welded structure are hardly performed for the large computational requirements. A new mesh division technique is set up in order to use 3D thermal-elastic-plastic FEM (finite element method) to simulate the welding process of thin Al alloy structure. A butt weld of a thin plate by using the division technique is investigated. The two different element division schemes are carried out for achieving the calculation efficiency of different schemes. A cylinder product’s welding process is also simulated. The welding residual stress and distortion are successfully obtained. All results indicate that using the new mesh division for thin structure is easier to perform and analysis time can be reduced greatly while high precision is still obtained.

Key words: Welding residual stress, Finite element method, Numerical simulation, Welding distortion, Ablation, Femtosecond laser, Functional surface, Precise machining, Two-photon absorption