结构损伤识别的附加质量方法

STRUCTURAL DAMAGE IDENTIFICATION BY ADDING GIVEN MASSES

提出一种仅需要频率信息就可以识别结构损伤的附加质量方法。通过在原结构上附加已知的集中质量块,测量所得附加质量系统的低阶频率信息,联合这些新的频率信息及原结构的频率信息来建立灵敏度方程求解损伤参数。以一个对称的简支梁结构为例验证了所提方法。结果表明:该方法仅利用结构振动的低阶频率信息就可以较好地完成损伤识别的任务。

A new method is proposed to identify structural damages only by changing the natural frequencies of the structure. By adding given masses to the physical structure, measuring the lower natural frequencies of the mass-modified structure, and then using these new data as well as the original test information, structural damages can be detected by using the eigenvalue perturbation technique. Regardless of whether the structure is unsymmetrical or symmetrical, the proposed method can successfully identify damages even if only the first few natural frequencies are measured. The approach offers the practical attraction of only requiring measurements of the changes in a few of the structural natural frequencies between the undamaged and damaged states. The paper also discussed the means of determining the number, placement and size of the added masses. The feasibility of the methodology is demonstrated analytically on a symmetrical beam structure. Results show that the proposed method may be a promising tool to be used in structural damage identification.