Affiliation:
1. Department of Mechanical & Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802
2. Department of Mechanical Engineering, University of Connecticut, Storrs, CT 06269
Abstract
The concept of using sensitivity-enhancing feedback control to improve the performance of frequency-shift-based structural damage identification has been recently explored. In previous studies, however, the feedback controller is designed to alter only the closed-loop eigenvalues, and the effect of closed-loop eigenvectors on the sensitivity enhancement performance has not been considered. In this research, it is shown that the sensitivity of the natural frequency shift to the damage in a multi-degree-of-freedom structure can be significantly influenced by the placement of both the eigenvalues and the eigenvectors. A constrained optimization problem is formulated to find the optimal assignment of both the closed-loop eigenvalues and eigenvectors, and then an optimal sensitivity-enhancing control is designed to achieve the desired closed-loop eigenstructure. Another advantage of this scheme is that the dataset of frequency measurement for damage identification can be enlarged by utilizing a series of closed-loop controls, which can be realized by activating different combinations of actuators in the system. Therefore, by using this proposed idea of multiple sensitivity-enhancing feedback controls, we can simultaneously address the two major limitations of frequency-shift-based damage identification: the low sensitivity of frequency shift to damage effects and the deficiency of frequency measurement data. A series of case studies are performed. It is demonstrated that the sensitivity of natural frequency shift to stiffness reduction can be significantly enhanced by using the designed sensitivity-enhancing feedback control, where the optimal placement of closed-loop eigenvectors plays a very important role. It is further verified that such sensitivity enhancement can directly benefit the damage identification accuracy and robustness.
Reference36 articles.
1. A Summary Review of Vibration-Based Damage Identification Methods;Doebling;Shock Vib. Dig.
2. Doebling, S. W., Farrar, C. R., Prime, M. B., and Shevitz, D. W., 1996, “Damage Identification and Health Monitoring of Structural and Mechanical Systems from Changes in their Vibration Characteristics: A Literature Review,” Los Alamos National Laboratory Report No. LA-13070-MS, Los Alamos, NM.
3. Comparative Study of Vibartion-Based Damage Identification Algorithms;Cornwell
4. Detection of Structural Damage Through Changes in Frequency: A Review;Salawu;Polym. Polym. Compos.
Cited by
28 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献