Boundary-enhanced reconstruction algorithm for probabilistic inspection of composite plate defects with air-coupled Lamb waves

Abstract

Abstract Air-coupled Lamb wave imaging is an emerging non-contact structural defect inspection method. The current imaging algorithms still face challenges such as imaging accuracy improving. In this work, a boundary-enhanced reconstruction algorithm for probabilistic inspection of damage (BERAPID) is proposed to improve the defect boundary imaging accuracy. The improvement is through a skewed distribution algorithm to adjust the energy distribution of the Lamb wave when it passes through the defect edge. The BERAPID algorithm compensates for the problem of boundary blur and defect expansion in traditional RAPID. The composite plate defect imaging system based on air-coupled Lamb waves is built to verify the improved algorithm. The evaluation indicators of imaging error and image contrast are presented for 6 different types of defects. The experimental results demonstrate that the BERAPID can effectively reduce the imaging error and improve the image contrast for defect boundaries.