磁驱动压-剪联合加载下材料动态强度的直接测量

Direct measurement of material dynamic strength under high pressure using magnetically driven pressure-shear loading

动高压下材料的屈服强度测量一直是冲击动力学界长期追求的目标.本文介绍了一种直接测量材料高压强度的新实验方法,即磁驱动压-剪联合加载实验技术.分析了压-剪联合作用下材料的应力偏量与屈服强度关系,数值计算了斜波加载下压-剪联合作用时应力偏量与屈服强度的时空演化,给出了强度数值的计算方法.基于CQ-4装置,开展了磁驱动斜波加载压-剪联合实验设计并对铝的高压强度进行了测量,获得了可靠的实验数据.实验结果表明,磁驱动压-剪联合加载技术作为一种全新的加载手段,在材料的动高压强度测量方面展示了广阔的应用前景.

Material strength measurement under high pressure is a long goal of impact dynamics. In this work, we report a new method for directly measuring material dynamic strength under high pressure, viz. magnetically driven pressure-shear loading technique. The relations of deviatonic stresses and yield stress under pressure-shear loading were analyzed, and simple functions of deviatonic stresses and yield stress were obtained under complex stress state. Using LS-DYNA code, evolutions ofdeviatonic stresses and Von-Mises stress in sample under ramp wave pressure-shear loading were simulated, and calculation method of material strength is given. Based on numerical simulations results, magnetically driven ramp wave pressure-shear experiments were conducted on pulsed power generator CQ-4, with established quasi-static magnetic field generator and transverse velocity measurement techniques, to explore dynamic strength of aluminum at high pressure. Reliable experimental results are obtained. The results show that, as a potential new technique, magnetically driven pressure-shear combination loading has great application prospect in material dynamic strength measurement under high pressure.