Michaël Brun

A PERFECTLY MATCHED LAYER FOR SEISMIC WAVE PROPAGATION IN UNBOUNDED DOMAIN BY USING HETEROGENEOUS MULTI-TIME STEP SUBDOMAIN METHODS.

Abstract. In the framework of the Finite Element Method, Perfectly Matched Layer (or PML) is recognized as a very effective tool for reproducing unbounded domains (Basu et al. [13]). Nonetheless, the computation time required by the PML may be large, especially when an explicit time integration scheme is adopted for dealing with the wave propagation problem both in the domain of interest and in the PML medium (Basu et al. [13]). The paper proposed to investigate subdomain strategies enabling to choose the appropriate time integration scheme in the PML with its own time step, independently on the choice of the explicit time scheme in the domain of interest associated with a fine time step satisfying the stability criterion (CFL condition). The investigated subdomain strategy, proposed by Gravouil and Combescure [14], is based on the Schur dual approach, characterized by the introduction of Lagrange multipliers at the interface between subdomains for ensuring the velocity continuity.