We present a novel method to simulate spontaneous nucleation of fault ruptures and the propagation of seismic waves thereafter. A discontinuous Galerkin method with penalty flux is utilized for discretization in space, and the rate- and state-dependent friction is taken into account in the form of a nonlinear transmitting boundary condition, which is weakly enforced across the fault surface as numerical flux. An iterative coupling scheme is developed to overcome the challenge of implicit time stepping, by splitting the state ODE, which is defined only on the rupture surface and solved by a high-order Runge–Kutta method with finer time stepping, from the linear elastic system which is defined on the 3D subdomains and solved using a standard time marching scheme. The coupling of the two parts is set up as a constrained optimization problem based on the force equilibrium, and solved by Newton–type methods. We test our algorithm on a well-established numerical example in 3D with a planar rupture intersecting the traction-free ground surface.
Presentation Date: Tuesday, September 26, 2017
Start Time: 4:20 PM
Location: 381A
Presentation Type: ORAL
