Jung Ho-Yeon, Sung Seung-Hoon, Jung Hyung-Jo
Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Korea.
Agency for Defense Development, Yusong P.O.Box 35, DaeJeon 305-600, Korea.
Sensors (Basel). 2015 Oct 16;15(10):26315-30. doi: 10.3390/s151026315.
In this study, we experimentally validated the normalized uniform load surface (NULS) curvature method, which has been developed recently to assess damage localization in beam-type structures. The normalization technique allows for the accurate assessment of damage localization with greater sensitivity irrespective of the damage location. In this study, damage to a simply supported beam was numerically and experimentally investigated on the basis of the changes in the NULS curvatures, which were estimated from the modal flexibility matrices obtained from the acceleration responses under an ambient excitation. Two damage scenarios were considered for the single damage case as well as the multiple damages case by reducing the bending stiffness (EI) of the affected element(s). Numerical simulations were performed using MATLAB as a preliminary step. During the validation experiments, a series of tests were performed. It was found that the damage locations could be identified successfully without any false-positive or false-negative detections using the proposed method. For comparison, the damage detection performances were compared with those of two other well-known methods based on the modal flexibility matrix, namely, the uniform load surface (ULS) method and the ULS curvature method. It was confirmed that the proposed method is more effective for investigating the damage locations of simply supported beams than the two conventional methods in terms of sensitivity to damage under measurement noise.
在本研究中，我们通过实验验证了归一化均匀载荷面（NULS）曲率法，该方法是最近为评估梁式结构中的损伤定位而开发的。归一化技术能够更准确地评估损伤定位，且具有更高的灵敏度，而与损伤位置无关。在本研究中，基于从环境激励下加速度响应获得的模态柔度矩阵估计出的NULS曲率变化，对简支梁的损伤进行了数值和实验研究。对于单一损伤情况以及多损伤情况，通过降低受影响单元的弯曲刚度（EI）来考虑两种损伤场景。作为初步步骤，使用MATLAB进行了数值模拟。在验证实验期间，进行了一系列测试。结果发现，使用所提出的方法可以成功识别损伤位置，且没有任何误报或漏报。为了进行比较，将损伤检测性能与基于模态柔度矩阵的其他两种知名方法，即均匀载荷面（ULS）法和ULS曲率法的性能进行了比较。结果证实，在所测量噪声下对损伤的灵敏度方面，所提出的方法在研究简支梁的损伤位置方面比两种传统方法更有效。
