A simple method to detect cracks in beam-like structures
A simple method to detect cracks in beam-like structures
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DOI：
10.12989/sss.2012.9.4.335
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发表时间：
2012-04
影响因子：
3.5
通讯作者：
J. Xiang;Toshiro Matsumoto;J. Long;Yanxue Wang;Zhansi Jiang
中科院分区：
文献类型：
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作者：
J. Xiang;Toshiro Matsumoto;J. Long;Yanxue Wang;Zhansi Jiang
本文提出了一种简单的基于结构振动的梁式结构健康监测的两步法，该方法仅利用结构的振型曲率和少量的固有频率来检测和定位裂纹。该方法首先基于小波变换的应用，从振型曲率检测裂纹位置。然后将粒子群优化算法应用于裂纹深度的估计。由于引入了瑞利商来估计裂纹梁的自振频率，因此自振频率与裂纹深度之间的关系只需一个简单的公式即可得到。该方法被证明和验证数值，使用的数值例子（悬臂梁和简支轴）在文献中，和实验的悬臂梁。我们的研究结果表明，模态曲率和一些估计的自然频率可以用来检测裂纹的位置和深度，即使在一定的噪声水平。该方法可以扩展到其他更复杂结构的健康监测。
This study suggests a simple two-step method for structural vibration-based health monitoring for beam-like structures which only utilizes mode shape curvature and few natural frequencies of the structures in order to detect and localize cracks. The method is firstly based on the application of wavelet transform to detect crack locations from mode shape curvature. Then particle swarm optimization is applied to evaluate crack depth. As the Rayleigh quotient is introduced to estimate natural frequencies of cracked beams, the relationship of natural frequencies and crack depths can be easily obtained with only a simple formula. The method is demonstrated and validated numerically, using the numerical examples (cantilever beam and simply supported shaft) in the literature, and experimentally for a cantilever beam. Our results show that mode shape curvature and few estimated natural frequencies can be used to detect crack locations and depths precisely even under a certain level of noise. The method can be extended for health monitoring of other more complicated structures.