Simulation on deforming progress and stress evolution during laser shock forming with finite element method

• A FEM model with the code LS-DYNA has been built to simulate LSF dynamic behaviors.
• Solution time should be set to ms level, which is greatly longer than that in LSP.
• Metal sheet first experiences shearing deformation and then stretch deformation.
• The temporal reverse deformation occurs in evolution of bulge shape.
• The depth of bulge firstly lasts increasing and then undergoes several spring backs.

Laser shock forming (LSF) employs laser shock wave to form metal sheet, which is similar to explosive forming. Finite element method (FEM) is an effective method to better understand mechanism of LSF and select appropriate parameters to shape metal sheet accurately with LSF. In this paper, FEM analysis model is developed to simulate LSF, which includes how to determine the pressure loading, material constitutive model, and solution time. The commercial code LS-DYNA is applied to simulation. A sequence of dynamic deformation behaviors of metal sheet at the end of different periods are presented and discussed in detail, and the peculiar phenomena in dynamic deformation processing are discovered, which do not appear in the traditional forming processing. The final static deformation and residual stress are also predicted. The predicted results are accordance with the experimental data.