On the absorbing boundaries to replicate semi-infinite half-space in numerical seismic analyses using the finite element method

PreviousNext No AccessSecond International Meeting for Applied Geoscience & EnergyOn the absorbing boundaries to replicate semi-infinite half-space in numerical seismic analyses using the finite element methodAuthors: Tyler R. HebertJames M. BryceArka Prabha ChattopadhyayTyler R. HebertMarshall UniversitySearch for more papers by this author, James M. BryceMarshall UniversitySearch for more papers by this author, and Arka Prabha ChattopadhyayMarshall UniversitySearch for more papers by this authorhttps://doi.org/10.1190/image2022-3751979.1 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail AbstractComputational analysis allows for easy replication of seismic tomography using numerical solving techniques. The Finite Element Method (FEM) and the Finite Difference Method (FDM) are the two primary methods which are used for such computational models that have been presented in the literature. One challenge of such analyses is the creation of a semi-infinite half space. In a monolithic, elastic domain, seismic waves propagate without any interruptions in the absence of domain boundaries. However, in a computational study, the geometry is of a finite volume and it is not possible to create a semi-infinite half-space without additional adjustments. To address this, certain boundary conditions which simulate the finite domain to behave like a semi-infinite half space are used. These conditions are enforced on the essential boundaries, which otherwise reflect the transient wave propagation. We call these conditions as absorbing layers, which trap the outbound waves at these boundaries, thus preventing reflection of the waves back into the domain of analysis. In this study, the efficacy of using different absorbing layers is investigated in the framework of the FEM formulation of the transient wave propagation in monolithic and multi-material linear elastic domains. We test three different methods of implementing absorbing layers into a computational model: Perfectly Matched Layers (PML), Caughey Absorbing Layer Method or Caughey Damping (CD), and Infinite Elements (IE). The assessment of CD and IE were performed in the commercial FEM software ABAQUS and were compared with benchmark computational results of PML from the literature. The quality of absorption was quantified based on the residual strain energy and displacements present in the domain of interest post interaction of the propagating waves with the absorbing layer. It was determined that the Infinite Elements provides an absorbing layer of reasonable accuracy at relative ease of implementation in seismic tomography simulations.Keywords: numerical seismic, finite element method, absorbing boundariesPermalink: https://doi.org/10.1190/image2022-3751979.1FiguresReferencesRelatedDetails Second International Meeting for Applied Geoscience & EnergyISSN (print):1052-3812 ISSN (online):1949-4645Copyright: 2022 Pages: 3694 publication data© 2022 Published in electronic format with permission by the Society of Exploration Geophysicists and the American Association of Petroleum GeologistsPublisher:Society of Exploration Geophysicists HistoryPublished Online: 15 Aug 2022 CITATION INFORMATION Tyler R. Hebert, James M. Bryce, and Arka Prabha Chattopadhyay, (2022), "On the absorbing boundaries to replicate semi-infinite half-space in numerical seismic analyses using the finite element method," SEG Technical Program Expanded Abstracts : 2576-2580. https://doi.org/10.1190/image2022-3751979.1 Plain-Language Summary Keywordsnumerical seismicfinite element methodabsorbing boundariesPDF DownloadLoading ...