A Baseline-Free Modal Strain Energy Method for Damage Localisation

This study describes the work carried out with the intention of accomplishing the ultimate objective of effective damage detection in structures, using their vibration parameters. As compared to the other vibration parameters, i.e., mode shape curvatures, damage indices, and flexibility curvatures, modal strain energy method (MSEM) showed high stability of damage detection. However, MSEM requires the information of a baseline model or healthy structure, which is then compared with that of a tested structure, to locate any stiffness reduction. In this paper, a baseline-free approach is presented to improve the accuracy of damage detection using the MSEM. Results from numerical simulations with experimental testing on a beam are presented by considering various damage scenarios, i.e., single and multiple damage with damage severity as small as 25% and as large as 50% thickness reduction. For all cases, the proposed approach is found to generate results with comparatively fewer noisy peaks in the damage index without requiring any reference or baseline data.