高孔隙率Al_2O_3微孔陶瓷压剪冲击动力学特性

Dynamic Responses of Alumina Microvoid Ceramics with High Porosity under Combined Pressure and Shear Impact Loading

基于一级压剪轻气炮，对高孔隙率Al2O3微孔陶瓷（孔隙率47%-50%）进行冲击速度为68-201 m/s、倾斜角为0-15°的平板撞击实验，研究了相关的动态压缩及剪切特性。结果表明，由于材料的气孔为直径小于5 μm的微孔，其压缩过程是一个渐进的均匀发展的过程，并没有孔洞崩塌现象发生；其剪切行为表现出脆性材料的一般特性。基于Hoek-Brown准则和帽盖模型，建立了孔隙介质动态破坏模型和动态双重屈服面模型。结合压剪实验数据，对模型进行了初步分析，分析结果表明了此模型的适用性。

Based on one-stage light gas gun, series of experiments including oblique planar impact with inclination angles of 0~15° and impact velocity ranging from 68 to 201 m/s were carried out to investigate the responses of alumina microvoid ceramics with high porosity subjected to impact loading. Experimental results show that since the diameter of microvoid in sample is smaller than 5 μm, the process of sample compression is gradually and evenly developed, and there is no porous collapse observed. The dynamic shear behaviors are similar to those of brittle materials. Based on the Hoek-Brown criteria and Cap-model, the dynamic model for the failure surface and the double yield surfaces of porous brittle materials was built. Based on the experimental data of compression and shear combined impact loading, the preliminary analyses were carried out and the results show the applicability of the model.