Detection and localization of low-velocity impact damages of composite structures based on wavelet analysis of modal shapes

The proposed method is based on non-destructive and non-contact measurements of displacements of modal shapes and then processing the acquired signals using spatial wavelet transform. The experimental studies were carried out on the laminated composite plates with artificially inputted impact damages with various energies of impacts and different geometric properties of impactors. The application of different impactors allows for simulation of different types of stress distributions (tension, shear or both stress components) and consequently different types of damages. The modal shapes acquired experimentally were analyzed using wavelet-based algorithm, which allow to extract diagnostic information about the damage presence and location. The results of the damage detection studies prove the effectiveness of the proposed method and a possibility of its practical application.