Yield behavior of polystyrene at strain rate 106/s under quasi-isentropic compression

Abstract

The yield behaviors of polystyrene(PS) were researched by means of the technique of magnetically driven quasi-isentropic compression on compact pulsed power generator CQ-4 for its better applications in protection structure designs and plastic bonded explosives. The experimental wave profiles of PS under quasi-isentropic compression exhibit obvious inflection point at the interface velocity of 50 m/s between PS and LiF window, from which the isentropic elastic limit is inferred to be 0.39 GPa at strain rate of 1 × 106/s and strain of 0.06. Based on Von Mises or Tresca yield criterion under one-dimensional strain, the initial yield strength of PS is derived to be 0.186 GPa, about 4 times the value of 0.04 GPa under quasi-static compression. The hydrodynamic simulations were conducted to describe the dynamic response of PS including the Mie–Grüneisen equation of state (EOS) and Steinberg–Guinan strength model. The yield response of PS under quasi-isentropic compression can be described well in our simulations, which shows excellent agreement with the experimental data.