000021657 001__ 21657
000021657 005__ 20170622131258.0
000021657 04107 $$aeng
000021657 046__ $$k2017-06-15
000021657 100__ $$aGlinsky, Nathalie
000021657 24500 $$aAN EFFICIENT HYBRID DISCONTINUOUS GALERKIN METHOD FOR THE WAVE PROPAGATION IN VISCOELASTIC MEDIA: APPLICATION TO LITHOLOGICAL SITE EFFECTS

000021657 24630 $$n6.$$pComputational Methods in Structural Dynamics and Earhquake Engineering
000021657 260__ $$bNational Technical University of Athens, 2017
000021657 506__ $$arestricted
000021657 520__ $$2eng$$aIn a few decades, numerical simulations became an essential tool for estimating ground motion under seismic loading. The study of site effects benefits of the development of accurate and efficient methods, allowing to tackle increasingly complex applications. For the study of P-SV waves propagation, we solve the velocity-stress system supposing that the medium is linear and viscoelastic. The medium attenuation is taken into account according to a Generalized Maxwell Body (GMB) method [EK87] considering n relaxation frequencies chosen in the frequency range of interest. This method is now well known and has been applied for various numerical methods (finite difference, spectral element). It results in a modified system containing additional equations for the anelastic functions (also called memory variables, 3n in 2D and 6n in 3D), describing the strain evolution inside the medium. For the solution of these equations, we propose a high order discontinuous Galerkin finite element (DG) method applicable to unstructured simplicial meshes [FP14]. As for standard finite element methods, the unknowns are approximated using a nodal Lagrange interpolation. But, since the method is discontinuous, the interpolants are defined locally in each mesh element, leading to small size local mass matrices, easily invertible even for high order interpolation. The link between the elements is performed by the numerical fluxes. The method has been validated in [FP14] for the study of lithological site effects using a realistic model of a basin in Nice. The major drawback of the GMB approach is the total number of unknowns, especially when a high interpolation degree and a reasonable number of mechanisms are used (generally between 3 and 5 relaxation frequencies).

000021657 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000021657 653__ $$a

000021657 7112_ $$aCOMPDYN 2017 - 6th International Thematic Conference$$cRhodes Island (GR)$$d2017-06-15 / 2017-06-17$$gCOMPDYN2017
000021657 720__ $$aGlinsky, Nathalie
000021657 8560_ $$ffischerc@itam.cas.cz
000021657 8564_ $$s118106$$uhttps://invenio.itam.cas.cz/record/21657/files/17407.pdf$$yOriginal version of the author's contribution as presented on CD, section: [MS10] Advances in Numerical Methods for Linear and Non-Linear Dynamics and Wave Propagation
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000021657 962__ $$r21500
000021657 980__ $$aPAPER