Effects of pores and inclusions on the elastoplastic behaviors of heterogeneous rock-like materials at same scale

The macroscopic mechanical behaviors of rock-like materials are influences by the microscopic features such as pores and mineral particles. However, most analytical solutions focus on the porosity or volume fraction of inclusions and generally consider this heterogeneity at different scales. In this paper, the traditional molecular dynamics based micromechanical modeling method is improved and combined with a Fast Fourier Transform (FFT) based numerical homogenization approach to investigate the effects of pores and inclusions, specifically their size, distribution, shape, and orientation, on the elastoplastic behavior of rock-like materials at the same scale. The macroscopic mechanical behaviors are investigated by considering perfect elastic mineral inclusions and pores distributed inside an elastoplastic solid matrix. Based on a series of numerical simulations, it is found that the distribution, the size, the shape and the orientation of pores and inclusions significantly influence the mechanical behaviors of rock-like materials. According to the microscopic stress distribution nephogram provided by the full field simulation, it is indicated that the essential reason for these effects lies in the different microscopic stresses induced by different microstructures of the pores and the inclusions. In particular, the interaction between pores and inclusions is quite strong and the presence of pores generally reduces the high stress area induce by the inclusions.