Saved in:
Bibliographic Details
Main Authors: Yang, Chen, Nakaoka, Junichi, Hirose, Sohichi
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2501.04039
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909450990780416
author Yang, Chen
Nakaoka, Junichi
Hirose, Sohichi
author_facet Yang, Chen
Nakaoka, Junichi
Hirose, Sohichi
contents In this paper, a three-dimensional Dirichlet-to-Neumann (DtN) finite element method (FEM) is developed to analyze the scattering of Lamb and SH guided waves due to a symmetric cavity defect in an isotropic infinite plate. During the finite element analysis, it is necessary to determine the far-field DtN conditions at virtual boundaries where both displacements and tractions are unknown. In this study, firstly, the scattered waves at the virtual boundaries are represented by a superposition of guided waves with unknown scattered coefficients. Secondly, utilizing the mode orthogonality, the unknown tractions at virtual boundaries are expressed in terms of the unknown scattered displacements at virtual boundaries via scattered coefficients. Thirdly, this relationship at virtual boundaries can be finally assembled into the global DtN-FEM matrix to solve the problem. This method is simple and elegant, which has advantages on dimension reduction and needs no absorption medium or perfectly matched layer to suppress the reflected waves compared to traditional FEM. Furthermore, the reflection and transmission coefficients of each guided mode can be directly obtained without post-processing. This proposed 3D DtN-FEM will be compared with boundary element method (BEM) and finally validated for several benchmark problems.
format Preprint
id arxiv_https___arxiv_org_abs_2501_04039
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Three-dimensional DtN-FEM scattering analysis of Lamb and SH guided waves by a symmetric cavity defect in an isotropic infinite plate
Yang, Chen
Nakaoka, Junichi
Hirose, Sohichi
Numerical Analysis
Computational Physics
In this paper, a three-dimensional Dirichlet-to-Neumann (DtN) finite element method (FEM) is developed to analyze the scattering of Lamb and SH guided waves due to a symmetric cavity defect in an isotropic infinite plate. During the finite element analysis, it is necessary to determine the far-field DtN conditions at virtual boundaries where both displacements and tractions are unknown. In this study, firstly, the scattered waves at the virtual boundaries are represented by a superposition of guided waves with unknown scattered coefficients. Secondly, utilizing the mode orthogonality, the unknown tractions at virtual boundaries are expressed in terms of the unknown scattered displacements at virtual boundaries via scattered coefficients. Thirdly, this relationship at virtual boundaries can be finally assembled into the global DtN-FEM matrix to solve the problem. This method is simple and elegant, which has advantages on dimension reduction and needs no absorption medium or perfectly matched layer to suppress the reflected waves compared to traditional FEM. Furthermore, the reflection and transmission coefficients of each guided mode can be directly obtained without post-processing. This proposed 3D DtN-FEM will be compared with boundary element method (BEM) and finally validated for several benchmark problems.
title Three-dimensional DtN-FEM scattering analysis of Lamb and SH guided waves by a symmetric cavity defect in an isotropic infinite plate
topic Numerical Analysis
Computational Physics
url https://arxiv.org/abs/2501.04039