材料强度对电磁驱动固体套筒内爆过程的影响

Effect of material strength on electromagnetic driven solid liner implosion

电磁驱动柱形固体套筒内爆加载技术是高能量密度物理实验研究的重要加载方式。由于固体金属具有一定的结合强度,需外加载荷达到特定阈值才会发生塑性流动,且在内爆过程中塑性做功会耗散部分电磁力做功而变成金属材料的内能,进而对固体套筒的内爆过程产生影响。通过弹塑性力学平面轴对称问题的解,给出了套筒发生塑性流动时外加电流(即屈服电流)与套筒参数的关系。利用考虑材料强度的零维不可压缩模型对铝套筒的内爆过程进行模拟,并分别与简单零维模型和实验数据进行对比,结果发现当电流峰值远大于(20倍于)屈服电流时,金属材料强度的影响甚微;而当峰值电流只数倍于屈服电流时,金属材料强度的影响便不能忽略。

The electromagnetic driven solid liner implosion is one of the high energy density physics(HEDP)experimental techniques.Because of the metal strength,there exists a threshold for driven pressure where plastic flow just begins.And the plastic work that will turn to the internal energy of the metal liner should decrease the kinetic energy of liner,which of course will affect the implosion of the solid liner.The critical current has been found via the elastic-plastic analysis of cylindrical symmetry issue.The zero-dimension(0D)simulation considering the effect of material strength has been developed,whose result is also compared with the simple model and experimental data separately.The result shows that the effect of material strength is negligible when the peak value of current is far larger than the critical current,while the effect is remarkable when the peak value is similar to the critical current.