How volumetric-deviatoric coupling influences the crack prediction in concrete fracture tests

The present paper analyzes the influence of volumetric-deviatoric coupling on the prediction of curved crack patterns in concrete fracture tests. The influence is analyzed by an elasto-plastic-damage model and the coupling is controlled by the hardening modulus of the plasticity model. First, the tangent stiffness matrix and the total stress-strain response for simple shear are investigated. Then, two fracture tests reported in the literature are simulated with significantly varying amounts of coupling. It is shown that volumetric-deviatoric coupling greatly improves the description of curved crack patterns in mixed-mode fracture tests.