Residual stresses and shakedown have been successfully presented by two‐dimensional numerical experiments based on the discrete element method (DEM), wherein a cohesionless‐frictional material under moving surface loads was replicated through irregular‐shaped particles. With surface loads below the shakedown limit, both permanent deformations and residual stresses cease to accumulate and the numerical structure shakes down after a number of load passes. Corresponding micro‐mechanical analyses indicate that strong forces and normal forces make a dominant contribution to residual stresses. Besides, averaged magnitudes of interparticle forces and corresponding total contact numbers initially change with load passes, and their final variation trends will differ as the structure shakes down or not. Furthermore, polar distributions of interparticle forces and contacts have been presented, and variations of their preferential orientations were emphasised. Lastly, the fabric tensor and anisotropy of resultant forces were studied, presenting the anisotropy weakening of macro‐stress fields, induced by developments of residual stresses.

中文翻译：

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移动表面载荷下无粘性摩擦颗粒材料的残余应力和安定的微机械分析


基于离散元法（DEM）的二维数值实验已经成功地呈现了残余应力和安定性，其中通过不规则形状的颗粒复制了移动表面载荷下的无粘性摩擦材料。当表面载荷低于安定极限时，永久变形和残余应力都停止累积，并且在多次载荷通过后，数值结构会发生振动。相应的微观机械分析表明，强力和法向力对残余应力起着主导作用。此外，颗粒间力的平均大小和相应的总接触数最初随载荷传递而变化，并且它们的最终变化趋势将随着结构振动与否而变化。此外，还提出了颗粒间力和接触的极性分布，并强调了它们的优先方向的变化。最后，研究了织物张量和合力的各向异性，揭示了残余应力的发展引起的宏观应力场的各向异性减弱。