When a dynamic earthquake rupture propagates on a fault in the Earth’s crust, the medium around the fault is dynamically damaged due to stress concentrations around the rupture tip. Recent field observations, laboratory experiments and canonical numerical models show the coseismic off-fault damage is essential to describe the coseismic off-fault deformation, rupture dynamics, radiation and overall energy budget. However, the numerical modeling of “localized” off-fault fractures remains a challenge mainly because of computational limitations and model formulation shortcomings. We thus developed a numerical framework for modeling coseismic off-fault fracture networks using the combined finite-discrete element method (FDEM), and we applied it to simulate dynamic ruptures with coseismic off-fault damage on various fault configurations. This paper addresses the role of coseismic off-fault damage on rupture dynamics associated with a planar fault, as a base case, and with a number of first-order geometrical complexities, such as fault kink, step-over and roughness.

当动态地震破裂在地壳的断层上传播时，断层周围的介质会由于破裂尖端周围的应力集中而受到动态破坏。最近的现场观察，实验室实验和规范的数值模型表明，同震断层破坏对于描述同震断层变形，破裂动力学，辐射和总能量收支至关重要。但是，“局部”断层断裂的数值模拟仍然是一个挑战，主要是因为计算上的局限性和模型制定上的缺陷。因此，我们开发了使用组合有限元法（FDEM）建模同震断层断裂网络的数值框架，并将其应用于模拟在各种断层构造下具有同震断层破坏的动态破裂。