A numerical study of effective mechanical behaviors of rock like materials based on Fast Fourier Transform

• A FFT-based micro-mechanical study is extended to nonlinear rock-like materials.
• Effects of various micro-structures on macroscopic behaviors are investigated.
• Plastic deformation and microcracking damage at mesoscopic scale are considered.
• The efficiency of the model is evaluated through comparisons with FEM solutions and experimental data.

This paper is devoted to the numerical modeling of effective mechanical behaviors of rock like materials by taking into account effects of micro-structure. The numerical model will be based on the Fast Fourier Transform (FFT) technique. We consider a class of rock materials with a microstructure which can be represented by a continuous matrix phase in which are embedded mineral inclusions. One or several constituent phases exhibit a nonlinear inelastic behavior. The proposed numerical model is firstly assessed by comparing numerical results with reference solutions obtained by direct finite element simulations. It will be then applied to a typical clayey rock which is constituted by an elastic–plastic clay matrix which is reinforced by linear elastic quartz and calcite grains. The proposed numerical model is further extended by including the progressive damage process due to the growth of micro-cracks. Comparisons between numerical results and experimental data will be presented to assess the efficiency of the numerical model.