Plastic penetration during laser heating of a metal plate

Based on Von Mises yield criterion and elasto-plastic constitutive relationship, a spacial axisymmetric finite element model of laser irradiating a metal plate is established. Taking nonlinear thermal and mechanical properties into account, temperature and stress fields generated by the continuous-wave Nd:YAG Gaussian laser beam in an aluminum alloy 2A12 plate are computed by the model. By the analysis of the results, the process that the plastic zone outspreads gradually and crosses the depth of the metal plate is observed. Consequently, the concept of metal plastic penetration is tentatively put forward and the applied range of this concept is discussed.