Abstract

A finite-element method to compute elastoacoustic vibration modes in 3D problems is analyzed. It is based on displacement formulations for solid and fluid. The discretization consists of classical isoparametric hexahedral elements for the former and hexahedral Raviart-Thomas elements for the latter, to avoid spurious modes. The meshes on fluid and solid domains do not need to coincide on the common interface, since the kinematic constraint is weakly imposed. The generalized eigenvalue problem is written in a matrix form which allows using a standard MATLAB eigensolver. Numerical results showing the good performance of the method and the convenience of using incompatible meshes are reported. © 2001 Acoustical Society of America.