【摘要】 采用一维弹塑性流体动力学计算方法,通过对LLNL(Lawrence Livermore National Laboratory)Mg-Cu体系密度梯度飞片冲击加载-准等熵加载实验过程数值计算和比较,验证了流体动力学计算方法、不同材料体系混合模型以及计算程序的正确性和实用性。考虑到在飞片材料制备中,单层厚度最小值为0.2 mm和Mg-W最大阻抗混合质量分数的致密条件限制,开展了对新的Mg-W体系密度梯度飞片实现冲击加载-准等熵加载过程计算设计,给出了满足加载要求的飞片结构特征;从计算给出的粒子速度波剖面可见,密度梯度飞片波阻抗分布对加载过程和加载强度非常敏感,通过精心设计准连续型变阻抗的梯度飞片,可以进行不同复杂加/卸载过程的物理模型设计和实验研究。更多还原

【Abstract】 The method of 1D elastic-plastic hydrodynamic calculations,the mixing model of different material constituents,and the shock dynamics code of compressible fluids were verified through the overall comparisons of the calculated results with the experimental data from Lawrence Livermore National Laboratory(LLNL).A Mg-W system prepared for graded density impactor(GDI) for quasi-isentropic compression was proposed by means of numerical simulations.By considering the actual material fabrication,the technical restrictions of minimum thickness of discrete layer,and the limitation of maximum mixing rate of the two individual constituents,a model GDI of a novel Mg-W system was designed to actualize the required loading traces and anchor the structural characteristics of GDI.Numerical calculations show that the loading path and intensity are highly sensitive to the distribution of wave impedance of GDI.The experimental designs and predictions for different complicated loading/unloading processes can be realized through model calculations.更多还原