A Dynamic Damage Statistical Constitutive Model of Rock Considering Strain Rate under Uniaxial Loading Conditions

Considering the dynamic deformation characteristics of rock and introducing the Kelvin model which consists of a viscous element and a paralleled elastoplastic element, a mechanical analysis model for rock under uniaxial loads is developed. This new model can take the influence of loading speed (or strain rate) and the dynamic behavior of rock into account. Based on that, with consideration of the influence of strain rate and volume change, a damage statistical constitutive model with the property of visco-elastoplastic is proposed by the statistical damage theory. Moreover, a method to determine the model parameters is presented. Finally, the proposed model is used to a practical problem, whose theoretical results are illustrated and compared to those of experiments. It is shown that the proposed constitutive model is effective to describe the characteristics of strength and elastic modulus of rock increasing with the increase of strain rate, and to simulate the dynamic deformation process of rock in uniaxial stress state.