Modeling of stress-strain dependences for Berea sandstone under quasistatic loading

In this work, a phenomenological model to describe the complex stress-strain properties of a sandstone sample under slow loading is presented. We consider a combination of three methods to treat the elastic and nonlinear behavior observed in stress cycling experiments. The mechanisms to treat interior equilibration processes in sandstone are termed the standard solid relaxation mechanism, the sticky-spring mechanism, and the permanent plastic deformation mechanism. With a small number of parameters, the overall model displays both qualitatively and quantitatively the principal experimental observations of the stress-strain trajectories for Berea sandstone, in particular, the details of end-point memory under quasistatic loading.