A computational approach to model dynamic contact and fracture mode transitions in rock

We propose an interfacial contact and fracture model based on Riemann solutions. Instead of penalty method and Lagrange multiplier approach we propose a regularization scheme—based on the interface displacement and separation velocity jumps—that smoothens contact-separation mode transitions. An aperture-based regularization approach smoothens the transfer of hydraulic load to in-situ cracks. A discontinuous Galerkin implementation is used to solve dynamic fracture problems for uniaxial compression and explosive examples. Moreover, we investigate contact–separation mode transitions and hydraulic load transfer in several hydraulic refracture problems and study the effect of loading rate and in-situ cracks in the number and orientation of activated perforations.