应变率和绝热软化对空腔膨胀影响的数值模拟

A Numerical Simulation of the Effects of Strain Rate and Adiabatic Softening on the Cavity Expansion Model

采用数值模拟的方法研究金属材料球形空腔膨胀的空腔面径向应力与膨胀速度关系。理想弹塑性模型和幂次硬化模型的模拟结果与理论解吻合得非常好,验证了该方法的有效性。在此基础上研究了应变率和绝热软化效应对空腔面径向力和膨胀速度的影响。结果表明,综合考虑应变率和热效应的侵深预测结果与试验值吻合得很好,只考虑应变率而不计热效应会高估侵彻阻力,造成侵深预测略为偏低,Warren解累积了材料可压缩性和不计热效应带来的误差,预测结果明显小于试验值。

A numerical method was used to study the relationship between the dynamic radial stress and the expanding velocity at a cavity wall in metal materials. The simulation results of the elastic-perfectly plastic and power-law model satisfied the theories＇ that proves the availability of the method. Then the influences of the strain-rate and adiabatic effects of the materials were analyzed by simulation. The re,hAts show that the predictions of penetration with the strain-rate and thermal effects of the materials corresponded well with the expefi.roents. The penetration resistance will be overvalued if the thermal effects were neglected, resulting in slightly lower penetration prediction. The predictions of Warren＇ s theory model are less than the experiments made in the current study because Warren＇s theory model accumulated the errors from compressibility but ignored the thermal softening.