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Accueil du site > Évènements > Séminaires > Séminaires LMA > Archives LMA > 2018

Mardi 5 Juin 2018 / LMA

publié le , mis à jour le

Séminaire LMA

A nodal discontinuous Galerkin method for modeling soil dynamics



Orateur : Diego Mercerat
CEREMA Méditerranée. Agence de Sophia Antipolis

Résumé : In this talk, I present some recent advances on seismic waves modeling in realistic media with elastoplastic behavior. After a brief introduction to the non-linear site response analysis in earthquake engineering, the capabilities of the discontinuous Galerkin finite element method (DG-FEM) are discussed in that framework. The method combines the geometrical flexibility of the finite element method, and the high parallelization potentiality and the capability for accurate simulations of non-linear wave phenomena of the finite volume technique. It has been successfully applied to elastic, visco-elastic and anisotropic media. The natural next step is to extend the method to elastoplastic soil rheologies found in the near subsurface. In our research group, we develop a discontinuous Galerkin method (nodal approach) for seismic waves in heterogeneous non-linear media. The method is based on high-order Lagrangian interpolation within the elements, upwind fluxes, and a fourth-order Runge-Kutta time scheme. The parallel Iwan model (Iwan, 1967) is used to account for the non-linear soil behavior, including hysteresis loops based on extended Masing rules. Comparison with different numerical methods shows satisfactory results for some canonical cases, for strains lower than 1%. Validation with real kik-Net data has been achieved within the Prenolin benchmark project.

References

Chabot S., Glinsky N., Mercerat D. and Bonilla F. (2017) A high-order discontinuous Galerkin method for 1D wave propagation in a nonlinear heterogeneous medium. Journal of Computational Physics, 355, doi : 10.1016/j.jcp.2017.11.013.

Chabot S., Glinsky N., Mercerat D. and Bonilla F. (2018) A high-order discontinuous Galerkin method for coupled wave propagation in 1D elastoplastic heterogeneous media. Journal of Theoretical and Computational Acoustics, accepted.

Iwan W.D. (1967). On a class of models for the yielding behavior of continuous and composite systems, J. Appl. Mech. 34, 612–617.

Regnier J. et al (2016) PRENOLIN : International Benchmark on 1D Nonlinear Site‐Response Analysis—Verification Phase Based on Canonical Cases. Bulletin of the Seismological Society of America 106(5):2112-2135.

Date et lieu : le 5 juin 2018 à 11h00, amphi du LMA