电子束引起的热击波和层裂破坏效应(英文)

THERMAL SHOCK WAVE AND SPALL FRACTURE CAUSED BY AN ELECTRON BEAM

本文对强流低能相对论电子束引起LT－12铝产生的热击波和层裂进行了分析．电子束在靶材中的能量沉积是非常复杂的，通常都用Monte－Carlo数值模拟的方法来计算能量沉积，本文发展了一种新的半经验解析方法．在研究由电子束引起材料的动态响应时，对于靶材表面的熔化过程要进行适当考虑，本文使用了GRAY三相状态方程，详细考虑了这种复杂的溶化过程．同时在研究层裂破坏效应及应力波的衰减规律时，放弃了通常的von—Mises流体弹塑性模型，而使用了应变率相关的本构模型．计算结果和实验结果比较一致．

Thermal shock wave and spall effect of LY - 12 aluminum exposed to a highcurrent and low energy electron beam are studied. The mechanism of energy deposition of electrons in the target is very complicated. Many researchers used the Monte - Carlo method to calculate the energy deposition, but a semi empirical method is used in this paper. The melting process should be adequately taken into account for the studies of the material dynamic response in the intermediate energy deposition range. The equation - of state (EOS) model used is a three - phase EOS which provides a more detailed and thermodyna.mically complete description of metals in the melting region. We also use the strain -rate -dependent constitutive modelwhich is more effective than the simple von - Mises elastic -plastic model in studying the spall fracture and the attenuation of the propagating stress waves. The heat -conduction effect is also considerd. The calculated results are in good agreement with the experimental results.