Damage identification in frame structures using high-speed digital image correlation and local modal filtration

摘要

This paper presents a technique for vibration-based damage detection and localization in engineering structures based on the high-speed three-dimensional Digital Image Correlation (HS 3D-DIC) and local modal filtration. The efficacy of the proposed procedure is demonstrated on a frame structure with different severities of localized damage. The full-field vibration data acquired under the white noise excitation provided the input to the damage identification algorithm. The spatial density of sensors on a test structure is one of the critical factors in the accurate localization of damage. Hence, the use of vision-based vibration measurement methods, such as the Digital Image Correlation (DIC) is very advantageous as it provides full-field quantification of dynamic displacement fields in three dimensions. Both numerical simulations with the use of Finite Element (FE) code and experimental tests with the use of high-speed digital cameras were performed to confirm the validity of the proposed approach. The research confirmed that it is feasible to use the proposed approach to detect and localize damage in a frame structure under random vibration excitation with a localization accuracy of a few percent of the field of view dimensions. On the basis of the obtained results, we believe that there is a great practical potential of this approach when applied to real-life engineering structures.