PBX压制过程中细观力学行为的二维数值模拟

应用圆形近似,建立了炸药颗粒随机分布的细观力学模型。进行了基于物质点法的奥克托今(HMX)基高聚物粘结炸药(PBX)炸药压制过程中力学行为的数值模拟。重点分析了压制过程中体系的应力和温度的变化以及晶体颗粒的变形。模拟结果表明,压制过程可以分为整合和巩固两个阶段。在整合阶段,颗粒受到压力而重新排列,应力产生于颗粒与压缩面的接触部分,并形成了多条的应力链。应力链沿炸药颗粒间的接触面向上和向下传播,体系在受力的过程中温度逐渐升高,体系局部最大温升为10K。体系进入巩固阶段的塑性形变过程后,内部应力梯度减小,同时体系内部明显存在温差,最大温差为20K。

Two Dimensional Numerical Simulation for Mesoscopic Mechanics Behaviors of PBX in Pressing Processes

A mesoscopic mechanics model of random distribution of explosive particles was constructed by applying circular approximation. The numerical simulation of mechanical behaviors in a pressing process of HMX based polymer bonded explosive (PBX) based on the material point method was carried out. The change in stress and temperature of the system and the deformation of explosive particles during the pressing process were emphatically examined. Simulation results show that the compression process can be divided into two stages: integration stage and consolidation stage. In the integration step, the explosive particles are subjected to pressure and rearrangement. The stress is produced at the contact part between explosive particles and compression surface, forming several stress trains and then the stress trains is propagated along the contact surface between explosive particles upward and downward. Temperature in the system gradually increases in the stress process. The maximum temperature rise in the locality of the system is 10 K. In the consolidation step, after the plastic deformation process of the system, the internal stress gradient decreases, at the same time, obvious temperature difference in the system is existed, the maximum temperature difference is 20 K.