Multi-damage localization in plate structure using frequency response function-based indices

11th International Conference on Damage Assessment of Structures

物理学;材料科学

Gao, Hai-Yang^1 ; Guo, Xing-Lin^2 ; Ouyang, Huajiang^2,3 ; Yang, Xiu-Ming^2

Beijing Institute of Spacecraft Environment Engineering, Beijing, China^1

State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian, China^2

University of Liverpool, Liverpool

L69 3BX, United Kingdom^3

关键词: Anti-noise ability;    Damage localization;    Different boundary condition;    Frequency response functions;    Gapped smoothing method;    Statistical treatment;    Structural damage detection;    Uniform load surface;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/628/1/012004/pdf
DOI  :  10.1088/1742-6596/628/1/012004

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Vibration signal and its derivative have shown some promise in structural damage detection in previous research. However, the theoretical and practical difficulties of multi-damage detection in plate structures based on dynamic responses remain. In this paper, an efficient damage localization index based on frequency response function (FRF) is presented. The imaginary part of FRF (IFRF) is extracted to derive the new localization index due to its relation to modal flexibility. For avoiding the finite element model error, two-dimensional gapped smoothing method (GSM) is employed without the need for baseline data from a presumably undamaged structure. Experimental studies on a steel plate with two localized defects in different boundary conditions are performed. The results are compared with some typical damage indices in the literature, such as mode shapes, uniform load surface and IFRF. In order to mitigate the inherent disadvantages of GSM in anti-noise ability, a simple statistical treatment based on Thompson outlier analysis is finally used for noise suppression. The effect of damage level and boundary condition on the detection results is also investigated.