Numerical simulation on attenuation of stress wave in copper target irradiated by intense laser

The code Abaqus/Explicit was employed to simulate on propagation of stress wave in a copper foil target, which was induced by intense laser with ns level width. A model was developed to simulate one dimensional planar stress wave propagation and attenuation, and its simulated model consisted of two kinds of elements: finite elements and infinite elements. Fine finite elements were used in laser shocked zone, and coarse infinite elements were used in surrounding zone as no reflecting boundaries. The strain rate effects and ultrahigh pressure effects on material yield stress were also considered. Series of simulations were performed using two different peak values, 0.35 GPa and 3.5 GPa, which were exerted on the target surface by shock wave. The two-step stress wave profile was obtained in copper target under the pressure of 3.5 GPa. The numerical results suggest that shock velocity is 4 600 m/s under the pressure of 0.35 GPa, and 4 000 m/s under the pressure of 3.5 GPa. The value of peak stress attenuates with the propagated distance in form of an exponential function. Some numerical results are in good agreement with the experimental results.