PBX炸药率型损伤本构关系的实验研究

Experimental Study on Rate-Dependent Constitutive Relations with Damage for Plastic-Bonded Explosives

利用万能材料试验机,对高聚物粘结炸药(PBX炸药)进行循环加、卸载实验和不同应变率下的压缩实验,测得PBX炸药在不同工况下的应力-应变曲线。采用唯象分析和细观统计相结合的方法,得到含损伤内变量的损伤演化方程,提出PBX炸药的率型损伤本构模型。通过拟合实验数据,获得了率型损伤本构模型的相关参数。结果表明,建立的本构方程能较好地描述PBX炸药在线弹性阶段、强化阶段、应变软化阶段的力学性能,待定参数少,形式简单,其中以微裂纹密度定义的损伤变量可方便地由力学实验确定。

Cyclic loading and unloading experiments and the uniaxial compressive experiment of plastic- bonded explosives （PBX） under different strain rate were performed by a universal material testing machine. The stress-strain curves of plastic-bonded explosives were obtained in different operating conditions. Based on the idea of combining pheno damage evolution equation with damage internal v damage for plastic-bonded explosives were given. menologieal analysis and micro-statistical analysis, a ariable and rate-dependent constitutive relations with The model was checked with the experimental data, and the relevant parameters of rate-dependent constitutive relations with damage were obtained. Experimental results indicate that the constitutive equation can describe mechanical properties of the PBX explosives at the linear elastic stage, strengthen stage, and strain softening stage. The constitutive relation is simple and requires less parameters to be determined. The damage variable defined by micro- crack density can be easily determined by mechanical testing.