Finite element analysis of deformation behaviour of circular sheet during laser forming process

Abstract

Laser forming of sheet metal involves inducing a bending process through the application of thermal stress using a defocused laser source. In laser forming the formation of bowl-shaped shapes requires the input of various laser process parameters. In this study, we investigate the thermo-mechanical deformation behaviour of a circular plate subjected to laser irradiation scanning. To analyse this phenomenon, we employ the Finite Element Method (FEM) with the aid of the software ABAQUS 6.10. The moving laser heat source is modelled as Gaussian heat flux, and DFLUX subroutine is written in FORTRAN. The work piece material AH36 is considered. The Finite Element Method (FEM) proposed model is verified against experimental results. Additionally, a parametric study has been conducted to assess the impact of laser process parameters on the temperature distribution of AH 36 material. The temperature distribution is noted to rise with an increase in laser power. However, as the scanning speed and laser beam diameter of the circular laser heat source increase, both temperature and bend angle exhibit a continuous decrease. Further, it is found the plastic strain is measured along the laser irradiation path, therefore the averaged material properties are not altered of the dome shaped obtained by laser forming. Based on the parametric studies, the optimum laser process parameters are also determined to get the dome shaped of the circular sheet.