Experimental and numerical investigation of structural damage detection using changes in natural frequencies

作     者：Xu, G. Y. Zhu, W. D. Emory, B. H. 

作者机构：Univ Maryland Baltimore Cty Dept Mech Engn Baltimore MD 21250 USA 

出 版 物：《JOURNAL OF VIBRATION AND ACOUSTICS-TRANSACTIONS OF THE ASME》 (美国机械工程师学会汇刊: 振动与声学杂志)

年 卷 期：2007年第129卷第6期

页      面：686-700页

核心收录：

学科分类：08[工学] 0802[工学-机械工程] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

主　　题：structural damage detection natural frequency changes perturbation method generalized inverse method iterative algorithm underdetermined system equations cantilever beams enrichment of measurement information ill-conditioned system equations 

摘      要：A robust iterative algorithm is used to identify the locations and extent of damage in beams using only the changes in their first several natural frequencies. The algorithm, which combines a first-order multiple-parameter perturbation method and the generalized inverse method, is tested extensively through experimental and numerical means on cantilever beams with different damage scenarios. If the damage is located at a position within 0-35% or 50-95% of the length of the beam from the cantilevered end, while the resulting system equations are severely underdetermined, the minimum norm solution from the generalized inverse method can lead to a solution that closely represents the desired solution at the end of iterations when the stiffness parameters of the undamaged structure are used as the initial stiffness parameters. If the damage is located at a position within 35-50% of the length of the beam from the cantilevered end, the resulting solution by using the stiffness parameters of the undamaged structure as the initial stiffness parameters deviates significantly from the desired solution. In this case, a new method is developed to enrich the measurement information by modifying the structure in a controlled manner and using the first several measured natural frequencies of the modified structure. A new method using singular value decomposition is also developed to handle the ill-conditioned system equations that occur in the experimental investigation by using the measured natural frequencies of the modified structure.