高应变率下颗粒增强复合材料动态力学行为

Dynamic mechanical behavior of particle reinforced composites under high strain rate

针对巡航导弹攻击地下目标过程中,在非预定目标深度出现战斗部颗粒增强复合材料装药提前起爆现象,研究颗粒增强复合材料装药在不同高应变率下的动态力学响应。基于改进的SHPB试验技术,实现常应变率加载及试件均匀变形,确保试验数据的可靠性,结合试验研究结果探索应变率效应对颗粒增强复合材料动态力学响应的影响规律,将应变与损伤变量耦合,揭示应力-应变比与颗粒增强复合材料弹性损伤的内在关联。结果表明:颗粒增强复合材料在高应变率为(400~2 200)s-1加载条件下的动态力学响应曲线呈非线性关系,具有明显应变率效应,随应变率的增大,应变强化效应由上凸特性转变为线性关系;结合有效应力及应变等效关系,将应变与损伤变量耦合,可描述颗粒增强复合材料在不同加载时期内损伤变量与轴向应力-应变比值之间的关系。

Aiming to the advance initiation phenomenon of particle reinforced composite charge occurs at non predetermined target depth in the course of cruise missile attacking the underground target, the dynamic mechanical response of particle reinforced composite charge was studied under different high strain rate. Based on the improved SHPB experimental technique, the constant strain rate loading and uniform deformation of specimen were ensured, and the dynamic behavior of particle reinforced composites was studied under different high strain rate loading. The influence of strain rate effect on dynamic mechanical response of particle reinforced composites was investigated. The intrinsic relationship between the ratio of stress to strain and elastic damage of particle reinforced composites was revealed by coupling the strain with the damage variable. The results show that the dynamic response curves of particle reinforced composites are highly nonlinear under different high strain rate（400-2 200） s-l loading and have obvious strain rate effect. With the increase of strain rate, the strain hardening effect is changed from the upper convex to the linear relation. Combining with the effective stress and strain equivalent relation, coupling the strain with the damage variable can correctly describe the relationship between the damage variable and the axial stress- strain ratio of the particle reinforced composite in different loading periods.