A Geometric Localization-Based Lamb-Wave-Assisted Method for Precise Damage Localization in Composite Materials

The research focuses on the problem of Lamb wave-based damage localization in composite materials and introduces a damage detection method based on geometric localization. The proposed approach determines the damage location by utilizing the geometric relationship between the damage site and transducers, considering the wave velocities of Lamb waves in various propagation directions and their corresponding Time of Flight (ToF). To characterize wave velocity, a dimensionless parameter k(θ) is introduced, and a theoretical model is employed to predict the velocity distribution of S0-mode Lamb waves in different lay-up configurations. ToF extraction is performed by applying a differential operation to the response signals in undamaged and damaged states, followed by complex Morlet wavelet transform analysis. Experimental results for [0/90]5 orthogonally laminated carbon fiber composites demonstrate that the proposed method achieves a localization error of no more than 5% for single-damage scenarios and approximately 6% for multiple damage scenarios. These findings validate the effectiveness and reliability of the approach for accurate damage localization under complex conditions, showing potential application prospects in the structural health monitoring of aerospace composite structures.