内爆加载金属界面不稳定性的数值分析

A numerical study of the instability of the metal shell in the implosion

采用自行研制的多介质弹塑性流体力学欧拉程序,对柱形内爆加载金属界面不稳定性进行了数值研究,数值模拟结果与文献实验数据吻合较好。数值结果表明:材料强度对界面不稳定性发展有不可忽略的抑制作用;材料屈服强度对较高模数不稳定性增长的抑制较强,而剪切模量对不稳定性发展的影响相似但敏感性相对较弱;金属界面不稳定性增长存在最不稳定模数,最不稳定模数随屈服强度增加而减小,并近似与屈服强度的对数呈线性关系;随着壳的厚度减小,扰动增长加快。

In this work the instability of the metal shell in the cylindrical implosion was studied numerically using a multi-component elastic-plastic hydrodynamic Eulerian code.Agreeing with those of the experiments,the numerical results show that the material strength restrains the growth of the interfacial perturbation with an effect not to be overlooked.The material yield strength has an obvious restraining effect on the higher mode of perturbation,while that of the shear module is similar but less sensitive.There exists a most instable mode number,which decreases as the yield strength increases and is approximately linear with the logarithm of the yield strength,and the perturbation grows faster as the shell grows thinner.