Modeling of Creep Behavior of an Argillaceous Rock by Numerical Homogenization Method

This paper is devoted to modeling the creep behavior of argillaceous rock and a comparison with experimental and numerical results from literature. The proposed time dependent modeling is based on a numerical homogenization method, matrix-inclusion material microstructure and a creep micro-mechanical model. The nonlinear viscosity of the argillaceous matrix is described by the creep model "Modified Time Hardening", while classical linear elasticity is applied for the calcite and quartz inclusions. The simulation accuracy was analyzed under single and multistage creep test. A satisfactory agreement between the simulation and the experimental results are obtained by assuming the main mineral phases of the Callovo-Oxfordian argillite. It was found that better agreements could be obtained when the multi-scale modeling is performed on sample with a given mineralogical composition and much more precisely volume fraction. The results show how numerical homogenization method is capable of effectively modelling macroscopic creep deformation.