混凝土等颗粒型材料的偶极效应分析

考虑物质点的偶极效应，基于 Cosserat 连续体介质力学模型，把球形微颗粒推广到方形微颗粒，推导出方形微颗粒对应的偶应力和曲率应变之间的线弹性关系，并提出了一种能考虑微颗粒倾覆破坏的广义屈服准则。编写了基于 Cosserat 连续体介质力学模型的有限元分析程序，进行了混凝土试样单轴压缩试验和土体边坡稳定性分析的数值模拟。研究结果表明，物质点的偶极效应确实存在，且是材料发生应变局部化的直接原因。

Dipole effect analysis of granular materials (such as concrete)

Within the framework of the Cosserat continuum medium mechanics model, the spherical micro particle is extended and transformed into a square micro particle with consideration of the dipole effect of material points. Based on the Cosserat continuum medium mechanics model, a linear elastic relationship between the couple stress and the curvature strain for the square micro particle is derived, and a generalized yield criterion that can consider the overturning failure of micro particles is put forward. With the finite element analysis program based on the Cosserat continuum medium mechanics model, a numerical simulation was performed in order to analyze the concrete specimens under uniaxial compression and the soil slope stability. The results show that the dipole effect of material points indeed exists, and it is a direct cause of strain localization of materials.