A RHEOLOGICAL MODEL OF A FRACTURED SOLID

Experiments to study the behavior of various materials point to the re lation that exists between elastic properties and the type of stress. The influence of the state of stress on the elasticity of a fractured material will be discussed for a physically non-linear model of an ela stic solid. The strain-dependent moduli model of material, presented i n this paper, makes it possible to describe this feature of a solid. I t also permits to simulate a dilatancy of rocks. A damage parameter, i ntroduced into the model using a thermodynamical approach, allows to d escribe a rheological transition from the ductile regime to the brittl e one, and to simulate the rock's memory, narrow fracture zone creatio n and strain rate localization. Additionally, the model enables the in vestigation of the final geometry of fracture zones, and also to simul ate their creation process, taking into account pre-existing fracture zones. The process of narrow fracture zone creation and strain rate lo calization was simulated numerically for single axis compression and s hear flow.