Sizing of interface delamination in a composite T-joint using Time-of-Flight of lamb waves

Abstract

The quantitative evaluation of the size of interface delamination in a glass/ epoxy (GFRP) composite T-joint is discussed here. An expression was derived to estimate the size of interface delamination from Time-of-Flight and group velocities of the fundamental anti-symmetric Lamb mode, A_o. Numerical simulations were carried out on [0₂/90₂]_s GFRP T-joint with different size of interface delaminations and validated with air-coupled ultrasonic experiments. The proposed methodology requires a baseline signal from a healthy region. Supplementary equations were presented to determine the error induced in the estimation of size of the interface delamination, due to mis-alignment during data collection.