Introduction of the method of finite-discrete elements into the Abaqus/Explicit software complex for modeling deformation and fracture of rocks

Abstract

The paper has considered development of a model within the framework of the method of finite-discrete elements for describing processes of rock deformation and fracture. Analysis of the methods of mathematical modeling of geomechanical processes which makes it possible to take into account the medium damage or fracture was presented. A physical model of rock fracture was proposed. It considers the fracture process as formation of microcracks of separation and shear or their combination. Examples of numerical modeling of loading a rock sample by the scheme of uniaxial compression and splitting by compression along generatrixes and in conditions of volume compression were considered. Formulation and results of simulation of development of a stress-strain state in the vicinity of the rock outcrop within the framework of the method of finitediscrete elements were presented. Within the framework of the study, an algorithm of implementing the method of finite-discrete elements in the Abaqus/ Explicit software complex for strength calculations including all main stages of forming the numerical model from generation of an elemental grid to specification of boundary conditions has been worked out. A software solution for generation of the elemental grid was developed and capabilities of the Abaqus/ Explicit software complex were expanded. This solution allows one to generate elemental grids for bodies of arbitrary shapes taking into account presence of surfaces of weakening within the body, both in flat and spatial formulations. The capabilities of the Abaqus/Explicit software complex were expanded in the field of modeling rock strength under the conditions of volumetric compression. According to the results of the performed studies, it was established that modeling of fracture formation (formation of shear and separation cracks) at the microlevel has allowed us to reliably represent processes of rock deformation and fracture. The possibility of using the method of finite-discrete elements for prediction of development of geomechanical processes in the vicinity of underground structures was presented. The presented study results allow us to extend the scope of the method of finite-discrete elements to solve the problems of geomechanics and form the basis for application of this method in solving engineering problems.