A pseudo local flexibility method for damage detection in hyperstatic beams

作者：Hsu Ting Yu^*; Liao Wen I; Shiao Shen Yuan

来源：Structural Control & Health Monitoring, 2015, 22(4): 682-693.

DOI：10.1002/stc.1713

• local flexibility method
• flexibility matrix
• damage detection
• beam
• vibration

Vibration-based damage detection methods make use of structural features extracted from vibration signals to perform damage diagnosis. The local flexibility method, which can determine local stiffness variations of beam structures by using measured modal parameters, is one of the more promising vibration-based approaches. The local flexibility method is founded on local' virtual forces that cause nonzero stresses within a local part of the structure. In this study, this basic rule has been broken. The pseudo-local' virtual forces that cause concentrated stresses in a local part and nonzero stresses in the other parts of a structure are employed. The theoretical basis of the proposed pseudo local flexibility method' (PLFM) is derived. The effects of the number of modes on the damage detection results are studied using both numerical and experimental hyperstatic beam models. The results show that significantly fewer modes are required for the PLFM to estimate the damage location and extent with acceptable accuracy. Therefore, the feasibility of the PLFM is higher because only a limited number of high-quality modes can be identified in real world applications. Furthermore, it was also found that when damage occurs close to the support, the PLFM is more likely to detect it, which is credited to the smaller local region induced by the PLFM.

• 出版日期2015-4