Changes of modal properties of simply-supported plane beams due to damages
Changes of modal properties of simply-supported plane beams due to damages
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DOI：
10.12989/imm.2009.2.2.153
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发表时间：
2009-06
期刊：
影响因子：
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通讯作者：
Z. Xiang;Yao Zhang
中科院分区：
文献类型：
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作者：
Z. Xiang;Yao Zhang
在过去的几十年里，使用结构动态响应的损伤检测方法受到了广泛的关注。对于桥梁和海上结构，这些方法通常基于梁模型。为了确保这些方法的成功应用，有必要检查模态特性对结构损伤的敏感性。为此，提出了简支欧拉-伯努利梁的模态特性的解析解，该梁包含一般损伤，没有附加假设。损坏可能是梁段内的弯曲刚度降低或质量损失。该解决方案使我们能够彻底讨论不同模态属性对各种损坏的敏感性。可以看出，当梁的截面损坏时，较低的固有频率和振型变化不大，而旋转角模式和曲率模式在损坏区域附近表现出突变。尽管之前已经报道过类似的观察结果，但本文提出的用于澄清所涉及机制的分析解决方案被认为是对文献的贡献。这有助于开发新的梁型结构损伤检测方法。
Damage detection methods using structural dynamic responses have received much attention in the past decades. For bridge and offshore structures, these methods are usually based on beam models. To ensure the successful application of these methods, it is necessary to examine the sensitivity of modal properties to structural damages. To this end, an analytic solution is presented of the modal properties of simply-supported Euler-Bernoulli beams that contain a general damage with no additional assumptions. The damage can be a reduction in the bending stiffness or a loss of mass within a beam segment. This solution enables us to thoroughly discuss the sensitivities of different modal properties to various damages. It is observed that the lower natural frequencies and mode shapes do not change so much when a section of the beam is damaged, while the mode of rotation angle and curvature modes show abrupt change near the damaged region. Although similar observations have been reported previously, the analytical solution presented herein for clarifying the mechanism involved is considered a contribution to the literature. It is helpful for developing new damage detection methods for structures of the beam type.