Fast multipole accelerated boundary integral equation method for 3-D elastodynamic problems in a half-space
Talk by Dr. Stéphanie Chaillat-Loseille
Speaker invited by: Prof. Dr. Stefan Sauter
Date: 20.03.14 Time: 15.30 - 16.30 Room: Y27H25
The presentation will provide an overview of recent works on improving the efficiency of the solution of elastic wave propagation problems in a half-space. The boundary element method (BEM) is used and accelerated by the fast multipole method (FMM).In a first part, I will show the principle of the FMM in elastodynamics, its implementation and capabilities on seismology-oriented examples.
To deal with problems in half-spaces, the method still suffers from the need to discretize the free surface. To avoid the problem of truncation, the boundary integral equation can be formulated with the fundamental solutions which intrinsically satisfy the traction free condition on the free surface. But the evaluation of these fundamental solutions and therefore the solution of the problem by the BEM is expensive and limits the use of this formulation. The second part of the presentation will be devoted to the definition of the multipole expansions for these fundamental solutions, the proposition of a new FMM and a discussion on the numerical difficulties related to the implementation. Finally, I will demonstrate the accuracy and capabilities this new FMM.