Simulation of three-dimensional transient temperature field during laser bending of sheet metal

Abstract

Laser bending is a flexible sheet metal forming process, its main mechanism, the temperature gradient mechanism, is forming by thermal stresses induced as a result of irradiation by a laser beam. Laser heating is an intensely transient heat transfer process, and does not conform to the classic Fourier heat transfer law. In this paper, on the basis of the non-Fourier heat transfer equation, with the effect of rate of heat transfer on temperature distribution taken into account, a computational model of temperature field is established. Then, the method of combined FEM with FDM is applied to analyse the three dimensional transient temperature field of the laser bending process. The influence of the time step size on the computed results is also discussed. A comparative study revealed that the temperature gradient in the sheet computed by the non-Fourier heat transfer equation is slightly larger than that computed by the classic Fourier heat transfer equation.