On the performance of vibro‐acoustic‐modulation‐based diagnosis of breathing cracks in thick, elastic slabs

Abstract

Vibro-acoustic modulation (VAM) is a nonlinear dynamics-based method for detecting damage in mechanical and structural components. Past studies have shown that VAM can be used for detecting contact acoustic nonlinearities and for mapping the extent of delamination or impact damage in thin composite plates. However, the suitability of VAM for mapping the extent of damage in thick, elastic slabs has not been studied. In this work, we investigate the performance of VAM in the context of localizing hidden, breathing cracks in thick elastic slabs using numerical simulations of the test procedure. We simulate the underlying nonlinear wave physics for two- or three-dimensional solids containing hidden cracks using the finite element method. We use our numerical model to perform computational VAM tests on elastic slabs containing cracks with known location and size. We propose a binary damage index for damage mapping, and we report on the sensitivity, specificity, and accuracy of the damage index-based damage localization procedure. We demonstrate the robustness of the damage localization procedure in the presence of measurement noise. We also perform parametric studies aimed at evaluating the effect of different test variables on damage detection and localization.