论文部分内容阅读
高聚物粘结炸药(PBX)是战斗部的关键组成部分,其动态力学行为,特别是动态断裂特性关系到战斗部的安全性和使用可靠性。基于内聚裂纹模型,对PBX模拟材料(PBX-M)的动态巴西实验进行数值模拟,对比霍普金森杆实验中测得的拉伸应力曲线,以及高速摄像结合数字图像相关方法得到的试样表面位移场和应变场。对比结果发现,拉伸应力峰值的数值模拟结果比实验结果小约5%,拉应变集中带的数值模拟结果与实验结果的偏差小于15%,验证了内聚裂纹模型的有效性。根据数值模拟结果,探讨了PBX-M试样在动态巴西实验过程中的起裂和裂纹扩展规律,给出了裂纹宽度的定量化信息。
Polymeric bonded explosives (PBXs) are a key component of warheads and their dynamic mechanical behavior, especially dynamic fracture properties, are related to the safety and operational reliability of warheads. Based on the cohesive crack model, the dynamic Brazilian experiment of PBX simulation material (PBX-M) was simulated. The tensile stress curve measured in the Hopkinson bar experiment was compared with that of the high-speed camera combined with the digital image correlation method Surface displacement and strain fields. The results show that the numerical simulation of the peak value of tensile stress is about 5% less than the experimental result, and the deviation between the numerical simulation results of the tensile strain concentration zone and the experimental result is less than 15%. The validity of the cohesive crack model is verified. Based on the numerical simulation results, the initiation and propagation of PBX-M specimens during the dynamic Brazilian test and the crack propagation are discussed. The quantitative information of crack width is given.