A Novel Approach for Quantitative Assessment of Delamination Damage Based on Vibrational Response

Abstract

Existing vibration-based approaches for damage detection are qualitative, providing indications of possible existence of damage. This paper presents a novel two-step approach for quantifying laminar damage, such as delamination in composites and thickness reduction in metallic structures due to corrosion damage. This new approach first employs a gap smoothing method to determine the location from curvature data from vibrational response. The severity of damage is then determined in the second step using an inverse method by matching predictions of finite-element analysis with deflection (or curvature) data. An assessment of various approaches for computing curvature reveals that wavelet transform is a promising method for simultaneously removing noise and computing curvature. Comparisons with experimental results show that this new two-step approach is capable of determining the size and severity of structural damage, which can be used as input for a residual strength assessment.