Investigation on Laser-Induced Shock Pressure with Condensed Matter Model and Experimental Verification

The laser-induced shock wave generated by the water confined regime in laser shock peening and its propagation in the Al2024 alloys are investigated theoretically and experimentally. Based on the condensed matter model, the pressure of plasma induced by homogenous nano-laser pulse is derived analytically and calculated from a simple partial differential equation. Using the derived plasma pressure as the input condition, the propagation of the shock wave in Al2024 is simulated by finite element method. The shock force at the back surface of Al2024 plate with different thickness were measured with polyvinylidene fluoride (PVDF) transducers and recorded by oscilloscope in the LSP experiment. By using water as a cushion at the Al0204-transducer and BK7-transducer interface, the impedance mismatch effect have been severely reduced. The experimental shock force profiles agree well with the simulated results, which indicates the analytical method based on the condensed matter model is an accurate way to conveniently calculate the laser-induced pressure from the laser power density.