RDX基含铝炸药的剪切试验及损伤模式

Shear Experiment and Damage Mode of RDX-based Aluminized Explosive

利用分离式霍普金森压杆(SHPB)试验设备及剪切装置,对RDX基含铝炸药进行剪切试验,获得了剪切力随时间的变化规律以及剪切应力,结合工业CT图像及电镜扫描(SEM)图像分析,探讨了剪切加载条件下,炸药试样破坏的宏观及微观损伤模式。结果表明,在剪切作用下,炸药装药的轴向应力-应变曲线出现两个阶段:第一阶段,较小的应变下,应力快速增加,最大值为50~60MPa;第二阶段,随着应变的增加,应力先增大后卸载。试验加载过程中的剪切应力为38~73kN;剪切应力小的试样,剪切带主要集中于加载面的中部,剪切应力大的试样,剪切带主要集中于剪切面附近;试样厚度较小时,损伤模式主要是晶体的微裂纹及晶体与黏结剂基体的脱粘,试样厚度增加时,损伤模式主要为晶体的多种形态。

Using shear apparatus equipped with the split Hopkinson pressure bar(SHPB)and cutting device,the variation rule of shear force with time and shear stress were obtained through the shear experiment on RDX based aluminized explosive.Combined with industrial CT images and scanning electron microscope(SEM)analysis,the macro/micro damage mode under shear loading condition was discussed.The results show that under the shear action,there are two extreme stages on the axial stress strain curves,the first stage is that the stress rapidly increases with a little strain,and the maximum value of this stress is about50-60MPa;the second stage is that the stress increases first and then unloads as the strain increases,and shear force is10-37kN in the loading process of this experiment.For small shear force specimen,the shear band mainly concentrats on the central section of loading surface,and for large shear force specimen,the shear band mainly concentrats on near the shear plane.When the specimen thickness is smaller,the damage mode mainly is micro crack of crystal and debonding of crystal and bonding agent matrix,when the thickness of specimen increases,the damage mode of specimen mainly is various forms of crystal.