Damage detection for plate-like structures using generalized curvature mode shape method

Abstract

Mode shape curvature-based method was originally developed to identify the damage in one-dimensional beam-like structures. In this paper, the method is generalized to fit for damage identification of plate-like structures, using two-dimensional mode shape curvatures. The modified method only requires the first few curvature mode shapes of the plate before and after damage, or only need modal information of the damaged plate if gapped smoothing technique is employed. To evaluate the effectiveness of the proposed method, numerical simulations considering various plate damage scenarios in terms of damage location, damage severity and multiple damages have been conducted, and experimental modal analysis on a steel plate with clamped and free edges is also performed to correlate with the numerical results. The final results show that the proposed method works well to detect the damage in a simple manner. For damaged structures, irregularities in their modal characterizations are induced at the places where local damages exist. Gapped smoothing technique takes advantage of smoothing functions and elevates the suggest method to be a reference-free approach. In the present study, a brief discussion has been performed and suggestions have been given concerning different smoothing functions used in the gapped smoothing technique.