SPH Simulation Of Thermal And Mechanical Response Of Material To Pulsed Laser Irradiation

Irradiated by laser, the temperature of material rise for energy deposition, and series of thermal and mechanical responses are introduced. In this paper Plenty of literatures are investigated related to the thermal and mechanical response of material to laser irradiation. Most of literatures only study melting, gasification and spatter of material induced by laser heating. Some research has shown that the reason of some disaster damage introduced by laser is mechanic not but melting. Keeping this fact in mind, it is investigated the problem of laser heating material in theory and simulation. The main aspects of research works in this paper are as follows:Interaction between laser and matter, the theory of absorption and reflection of the laser on medium, and the laser-induced temperature field of matter are discussed; Equation on the thermo-mechanical coupling theory is given. The discrete form of equations to solve the problem of Thermo-mechanical Coupling is obtained by the improved Smoothen Particle Hydrodynamics method, on the basis of studying thoroughly on the principle of Smoothen Particle Hydrodynamics method. A program using the SPH method is generated to compute the heat conduction effect of initial temperature discontinuity and invariable boundary temperature. Compared to the analytic solution, good agreement is achieved. Further simulations of thermal stress caused by instant temperature fluctuation and the square pulse laser irradiation are performed. The basic characters of thermal shock wave have been analyzed. The effect of laser intensity and laser pulse width to thermal stress and the effect of Thermo-mechanical Coupling item in heat conduction equation are discussed.