Damage Detection on Real-World Structures Through M-DLAC Technique

The localization of structural damage using non-destructive evaluation techniques based on changes in modal parameters is a significant challenge in the Structural Health Monitoring field. In this study, through the use of real-world data, we test a technique for structural assessment that relies solely on variations in natural frequencies induced by damage: the Multiple-Damage Location Assurance Criterion (M-DLAC). The findings shown represent a novel and significant contribution to the scientific community, as the M-DLAC technique has never been tested on real-world structures before. This is facilitated by the recent introduction in the literature of a benchmark structure database consisting of a 9-m-high lattice tower with reversible damage mechanisms at various levels. The aforementioned database encompasses the monitoring of the structure, in terms of accelerometer data, conducted over an entire year and includes various damage cases as well as the intact one. Moreover, the application of M-DLAC to the lattice tower necessitated the extension of the original method with a custom-built algorithm that uses mode shapes to correlate the post-damage modes with the pre-damage ones in order to successfully evaluate the natural frequencies variations. The study demonstrates the applicability and effectiveness of M-DLAC in real-world scenarios, highlighting its potential as a valuable tool for damage localization.