Application of Boundary Element Method superposition technique for solving natural frequencies in piecewise homogeneous domains

摘要

In this work, the domain superposition technique of the Boundary Element Method is coupled with the direct interpolation procedure to identifying the natural frequencies spectrum in two-dimensional piecewise domains with non-regular boundaries and internal inclusions. This problem can be addressed by well-established methods as Finite Element Method; however, the proposed methodology provides better results concerning the accuracy using a simple and expedite boundary element model. Solving the eigenvalue problem, the numerical quality of the matrix related to inertia can be evaluated more precisely, since it is approximated by radial basis functions. That is very important aiming future applications approaching wave propagation problems. A scalar acoustic and isotropic model is assumed, although the methodology can extend to the anisotropic materials. For better accuracy evaluation of the proposed methodology, the solution of some test problems is compared with those obtained with the Finite Element Method using fairly refined meshes. (C) 2019 Published by Elsevier Ltd.