高聚物粘结炸药动态损伤破坏的数值刻画

高聚物粘结炸药(PBX)安全性评估离不开对其力学响应和损伤破坏的刻画。为了准确捕捉PBX炸药的力学行为，以Karagozian & Case模型框架为基础，开展了PBX炸药力学行为数值刻画的研究。修改Karagozian & Case模型中的损伤演化方式，考虑PBX炸药模量、损伤演化模式等压力依赖特性。结合法国原子能委员会Picart等给出的一系列试验数据，修正Karagozian & Case模型中的应变率效应，分析不同压力下PBX炸药拉压子午线之比的取值，处理结构损伤破坏过程中变形局部化的问题，提出数值计算中拉伸失效单元的处理方法。得到的模型很好地刻画了Steven 试验中炸药试件的成坑形貌，并成功捕捉到了炸药试件中的拉伸、剪切破坏图像。

Numerical Characterization of Dynamic Damage of PBX Explosive

The safety assessment of PBX explosive is inseparable from the characterization of its mechanical response and damage. In order to accurately capture the mechanical behavior of PBX explosive, the numerical characterization method of PBX explosive mechanical behavior is studied based on Karagozian & Case (K&C) model framework. The damage evolution mode in the K&C model is modified, and the pressure-dependent characteristics of PBX explosive modulus and damage evolution mode are considered. Based on a series of published experimental data, the strain rate effect in the K&C model was corrected, the ratio of tension to compression meridian of PBX under different pressures was discussed, the deformation localization in the process of structural damage was dealt with, and the treatment of the tensile failure unit in the calculation was presented. The proposed model can be used to well depict the cratering morphology of explosive specimen in the Steven test, and successfully capture the tensile and shear failure images of explosive specimen.