A novel elastic-plastic damage model for rock materials considering micro-structural degradation due to cyclic fatigue

In this work, a novel constitutive model is developed to describe the mechanical behavior of rock like materials subjected to cyclic loading. The fatigue damage is physically related to the progressive micro-structural degradation which is described by a convolutional law. The number of cycles is considered as an equivalent time in the description of creep deformation. The fatigue damage evolution is further coupled with the plastic deformation. The evolution of fatigue damage is driven by the applied stress amplitude and number of cycles through the coupling with the accumulated plastic deformation. The proposed model is able to describe the mechanical responses of materials under both monotonic and cyclic loading conditions. The mechanical responses of two representative rocks, argillaceous quartz siltstone and salt rock, are investigated by the proposed model. All main behavior features of these materials are well captured by the proposed model.

Automated summary

In this work, a novel constitutive model is developed to describe the mechanical behavior of rock-like materials under cyclic loading. The model incorporates the fatigue damage related to micro-structural degradation, creep deformation, and plastic deformation. The proposed model accurately captures the mechanical responses of different rocks under both monotonic and cyclic loading conditions.