M.H Soorgee - Assistant Professor, Nondestructive Testing Lab., Faculty of Mechanical and Energy Engineering, Shahid Beheshti University, Tehran, Iran,

This paper is a numerical extension to the previous work done by the author on crack depth study in homogenous plates using Lamb wave based features. Based on 2D numerical simulations, it has been shown that, for pure S0 mode excitation, the amplitude ratio of both converted A0 mode, to the scattered S0 mode, in both transmitted and reflected waves from a crack, varies linearly as the crack depth changes. The goal of this paper is to verify this phenomenon via three dimensional finite element simulations. It is seen that from the mode conversion based amplitude ratios, ARR and ART, obtained from 2D simulation of wave interaction with the crack, for crack depth evaluation, ARR decreases monotonically in 3D simulation too, except for dc=0.2th, and can be employed for crack depth evaluation in real crack detection

Lamb waves, symmetric modes, mode conversion, crack depth, finite element method