Suggested Citation:
Lopez, Israel and Nesrin Sarigul-Klijn (2008) System Identification and Damage Assessment of Deteriorating Hysteretic Structures. Proceedings of the 49th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Confer

Assessment of impact damage in deteriorating structures is important as it can have potential benefits in improving their safety and performance. Most of the available damage assessment techniques are capable of detecting damage, location and/or severity; however, none of the available techniques provide an approach that can take into account structural deterioration in the parameter estimation, and results classification. Structures exhibit certain level of hysteretic behavior due to for example hydraulic systems of control surfaces, free-play of structural joints, and/or accumulated structural damage. In order to capture the uncertainty in estimating system parameters due to structural deterioration, our paper presents a modified exponential forgetting and resetting algorithm (MEFRA) for adaptive system identification to assess impact damage of time-varying hysteretic structures using vibration measurements. In our research, modal and time series parameters are to be identified using measured structural response from an undamaged system and then from a damaged system. Once the model structure is known, the problem of system identification is reduced to an adaptive parameter estimation and tracking. Individual and combined binary classification techniques are utilized to search for the most probable class of event by comparing the relative probabilities for impact damages. The effectiveness and robustness of our damage assessment approach is evaluated via computational simulations and next an overall comparison of the classifiers is given.