A new hybrid numerical scheme for modeling elastodynamics in unbounded media with near-source heterogeneities

TL;DR

This paper introduces a hybrid numerical scheme combining Finite Difference and Spectral Boundary Integral methods to efficiently model elastodynamics in unbounded media with near-source heterogeneities, validated through dynamic rupture examples.

Contribution

It presents a novel hybrid approach that integrates FD and SBI methods for improved modeling of elastodynamics with heterogeneities, enhancing computational efficiency and accuracy.

Findings

Successfully modeled dynamic rupture with heterogeneities

Validated the hybrid scheme with two example cases

Discussed potential applications in earthquake simulations

Abstract

The Finite Difference (FD) and the Spectral Boundary Integral (SBI) methods have been used extensively to model spontaneously propagating shear cracks in a variety of engineering and geophysical applications. In this paper, we propose a new modeling approach, in which these two methods are combined through consistent exchange of boundary tractions and displacements. Benefiting from the flexibility of FD and the efficiency of spectral boundary integral (SBI) methods, the proposed hybrid scheme will solve a wide range of problems in a computationally efficient way. We demonstrate the validity of the approach using two examples for dynamic rupture propagation: one in the presence of a low velocity layer and the other in which off-fault plasticity is permitted. We discuss possible potential uses of the hybrid scheme in earthquake cycle simulations as well as an exact absorbing boundary condition