This article presents the results of level-set (LS) discrete element method (DEM) simulations with experimental comparisons of flexible boundary plane strain tests in granular media. The grain-scale micromechanics at the particle level is captured well with LS-DEM, while the overall macroscopic response of the specimen is in quite good agreement with the simulation results. Onset and evolution of localized zones of shear strain accompanied by a significant amount of grain rotation could be well apprehended in the simulations, while the bulging of the specimen could be noticed in the experimental findings as well as in the model predictions. Multiple zones of shear strain accumulation in conjugate arrays were also observed on subsequent biaxial shearing of the sand specimen. The computational results furnish a quantitative estimate of the evolution of force chains and grain fabric orientation. Initially, these force chains were isotropic which on further deformation oriented in the direction of loading, and the grains aligned themselves in their preferred fabric orientation and remained in that fashion till the end of biaxial loading.

本文介绍了水平集（LS）离散元方法（DEM）模拟的结果，以及在颗粒介质中进行柔性边界平面应变测试的实验比较。LS-DEM可以很好地捕获颗粒级的晶粒尺度微力学，而标本的整体宏观响应与模拟结果非常吻合。在模拟中可以很好地理解剪切应变局部区域的发生和演化以及大量的晶粒旋转，而在实验结果和模型预测中可以注意到试样的膨胀。在随后的砂岩样品双轴剪切过程中，也观察到共轭阵列中剪切应变累积的多个区域。计算结果提供了力链和织物定向的演变的定量估计。最初，这些力链是各向同性的，在沿加载方向进一步变形时取向，并且晶粒以其优选的织物取向对齐，并以这种方式保留直到双轴加载结束。