Scattering Analysis of Lamb Waves at Subsurface Cracks in Isotropic Plates

The present work investigates the scattering behavior of a circular subsurface crack in isotropic material for an incident asymmetric A0 Lamb wave by a finite element (FE) model. This local FE model is designed according to the combined analytical finite element approach (CAFA) and uses a steady-state analysis in combination with non-reflective boundaries (NRB). The basic idea of CAFA is presented and the used FE model is explained in detail. The crack parameters size and depth are varied and the dependency of the scattered wave field on these parameters is analyzed by comparing the wave damage interaction coefficients (WDICs). The comparison of the WDICs show dependencies on the crack parameters for particular directions and observed trends are reported. Furthermore, conclusions on the future applications of found results are given.