PBX模拟炸药的动态力学行为及损伤本构研究

Research on Dynamic Mechanical Behavior and Damage Constitutive Model of PBX Substitute Material

针对实验室开展某些弹药力学响应实验时存在的安全问题,制备了PBX模拟炸药并研究了其力学性能,获得了不同应变率下的力学响应过程,并与PBX9501进行了对比;建立了PBS模拟炸药的广义黏弹性统计损伤本构模型(Vicso-SCRAM),利用有限元ABAQUS中VUMAT模块编写子程序,模拟了PBS模拟炸药的SHPB动态压缩实验,验证了所建立的损伤本构模型的有效性;利用SEM扫描电镜观察了PBS加载前后的细观形貌。结果表明,PBS材料具有明显的应变率效应,且其静态/动态力学性能与压装PBX比较相似;PBS细观结构及损伤形貌与PBX较为相似,在准静态加载条件下PBS材料主要发生黏结剂脱粘,在动态加载条件下则以穿晶断裂为主。

Aiming at the safety problems existing in some ammunition mechanical response experiments in the laboratory,PBX substitute material(PBS)was prepared and its mechanical behaviors were studied.The mechanical properties of the PBS were obtained under the different strain rates,which were compared with those of PBX9501.Viscoelastic statistical crack mechanics(Visco-SCRAM)was developed for the PBS.By using the VUMAT module of ABAQUS,the SHPB dynamic compression experiment of PBS was numerically studied,and the validity of the damage constitutive model was also verified.The microstructure of the PBS before and after loading were observed by SEM.The results show that the PBS has an obvious strain rate effect,and its static/dynamic mechanical properties are similar to that of pressed PBX.The microstructure and damage mode of the PBS were similar to that of the PBX.Under the quasi-static loading condition,interface debonding between the grain and polymer binder is the predominant failure mode.Under the dynamic loading condition,crystal cleavage is mainly damage mode.