Numerical simulation of Lamb wave scattering in semi-infinite plates

A 2nite element formulation is applied to study Lamb wave scattering in homogeneous and sandwich isotropic plates. Dispersion curves are calculated in a simple and automatic way by solving a quadratic eigenproblem. A meshing criterion to obtain accurate results with linear and quadratic elements is provided. An absorbing boundary condition for semi-in2nite plates is derived from this formulation by means of a truncated normal mode expansion technique, where the 2nite element eigenvectors are used instead of the analytical expressions for the normal modes. This non-reraction problems by defects with more complex geometries, a hybrid boundary element-2nite element formulation is developed. The validity and accuracy of both formulations are checked thoroughly with a series of test problems studied by other researchers