基于细观结构的颗粒介质应力应变关系研究

Microscopic study on stress-strain relation of granular materials

用DEM数值计算了一个颗粒介质的双轴压缩试验,分析了颗粒介质在等向压缩与剪切过程中颗粒细观结构的变化规律,推导出一个基于颗粒细观结构变化的颗粒介质屈服函数,其形式与修正剑桥模型的屈服面相似.利用该屈服面方程,可以通过颗粒接点数按接触角整理的分布变化说明在压缩和剪切过程中颗粒介质的屈服特性,为从颗粒细观结构的变化规律进一步研究颗粒介质的应力-应变特性提供了一个可行的方法.

A biaxial compression test on granular materials is numerically simulated by discrete element method （DEM）. The evolution of the microstructures of granular materials during isotropic compression and shearing is investigated, on which a yield function is derived. The new yield function is similar to the modified Cam-clay model and explains the yield behaviors of granular materials under isotropic compression and shearing by the distribution of the contact angles of particles.