Damage identification in structures using the time-domain response

A methodology to locate and size damage in a structure using the time-domain response is presented in this paper. The measured response in the time domain is spatially expanded over the structure and the mean strain energy for a specified time interval is obtained for each element of the structure. The mean strain energy for each element is, in turn, used to build a damage index that represents the ratio of the stiffness parameter of the pre-damaged to the post-damaged structure. The damage indices are used to identify possible locations and corresponding severities of damage in the structure. The validity of the methodology is demonstrated using data from a numerical example of a beam structure.