Damage localization by statistical evaluation of signal-processed mode shapes

11th International Conference on Damage Assessment of Structures

物理学;材料科学

Ulriksen, M.D.^1 ; Damkilde, L.^1

Dept. of Civil Engineering, Aalborg University, Niels Bolirs Vej 8, Esbjerg, Denmark^1

关键词: Continuous wavelet;    Damage localization;    Euler Bernoulli beams;    Mathematical method;    Noisy conditions;    Statistical evaluation;    Structural damage identification;    Structural information;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/628/1/012121/pdf
DOI  :  10.1088/1742-6596/628/1/012121

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Due to their inherent, ability to provide structural information on a local level, mode shapes and t.lieir derivatives are utilized extensively for structural damage identification. Typically, more or less advanced mathematical methods are implemented to identify damage-induced discontinuities in the spatial mode shape signals, hereby potentially facilitating damage detection and/or localization. However, by being based on distinguishing damage-induced discontinuities from other signal irregularities, an intrinsic deficiency in these methods is the high sensitivity towards measurement, noise. The present, article introduces a damage localization method which, compared to the conventional mode shape-based methods, has greatly enhanced robustness towards measurement, noise. The method is based on signal processing of spatial mode shapes by means of continuous wavelet, transformation (CWT) and subsequent, application of a generalized discrete Teager-Kaiser energy operator (GDTKEO) to identify damage-induced mode shape discontinuities. In order to evaluate whether the identified discontinuities are in fact, damage-induced, outlier analysis of principal components of the signal-processed mode shapes is conducted on the basis of T2-statistics. The proposed method is demonstrated in the context, of analytical work with a free-vibrating Euler-Bernoulli beam under noisy conditions.