不同加载速度下脆性颗粒的破坏特性

Fracture characteristics of brittle particles at different loading velocities

对直径为8mm的K9玻璃球进行了加载速度为2×10-7和2×10-6 m/s的准静态单轴压缩实验以及加载速度为3.4、7.1和10.6m/s的动态单轴压缩实验,研究了K9玻璃单颗粒破碎强度的Weibull分布特性,结合破碎产物的形貌特征,分析了不同加载速度下脆性材料拉伸破坏机制和剪切破坏机制的转变过程,提出了一种拉剪耦合的时序破坏模型,由此揭示了加载速度与3个破坏区的关系。考虑拉伸和剪切失效准则,应用ABAQUS软件进行数值模拟,并初步验证了该破坏模型的冲击过程。研究结果对于认识脆性颗粒材料的动态破坏具有很好的参考意义。

Uniaxial compression experiments of K9 glass spheres with a diameter of 8 mm were conducted to obtain the fracture responses of brittle particles at five loading velocities, i. e. 2 × 10 r and 2×10-6m/s for quasi-static loading and 3.4, 7.1 and 10.6 m/s for impact loading using a split Hop kinson pressure bar. Based on the Weibull distribution and recovery specimen products, a novel model combing the tensile failure and the shear failure was proposed to explain the process of the breaking evolution, revealing the relationship of the loading velocity and the three breaking zones. The model was validated using numerical simulation. Our study can serve as valuable reference for the study of the dynamic failure of brittle granular materials.