Dynamic analysis on laser forming of square metal sheet to spherical dome

Laser forming (LF) is a new die-less forming technique that employs the energy from a laser beam to modify and adjust the curvature of sheet metals. In order to advance the LF process further for realistic application industry, it is necessary to consider large scale three-dimensional laser forming (3DLF). The main problem of 3DLF is the understanding of the mechanism and the planning of laser scanning strategy. This paper illustrates the temperature field, stress-strain field, and deformation field in the process of 3DLF of square sheet to spherical dome with spider-lines strategy with a finite element method (FEM). The explicit dynamic integral is used in the work presented in the paper rather than implicit method for improving the computational efficiency and accuracy. The FEM results showed that the inner stress induced by the laser beam propagates through the sheet as a stress wave, and the thermal stress and the stress wave in the sheet are the main influence factors in 3DLF. Also, the FEM results have been verified against experimental data, and a reasonable correlation has been found. The work showed in the paper would be beneficial of the parameter optimization of laser scanning strategy and the control of the formed precision of the sheet in 3DLF.