Damage detection in multi-span beams based on the analysis of frequency changes

12th International Conference on Damage Assessment of Structures

Gillich, G.R.^1 ; Ntakpe, J.L.^1,2 ; Abdel Wahab, M.^3 ; Praisach, Z.I.^1 ; Mimis, M.C.^1

NDT Laboratory, Faculty of Engineering and Management, Eftimie Murgu University of Resita, Romania^1

Alphabet International GmbH, Munich, Germany^2

Laboratory Soete, Faculty of Engineering and Architecture, Ghent University, Belgium^3

关键词: Crack identification;    Frequency changes;    Frequency resolutions;    Identification method;    Intermediate support;    Modal strain energy;    Practical engineering;    Signal processing algorithms;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/842/1/012033/pdf
DOI  :  10.1088/1742-6596/842/1/012033

来源: IOP

【 摘 要 】

Crack identification in multi-span beams is performed to determine whether the structure is healthy or not. Among all crack identification methods, these based on measured natural frequency changes present the advantage of simplicity and easy to use in practical engineering. To accurately identify the cracks characteristics for multi-span beam structure, a mathematical model is established, which can predict frequency changes for any boundary conditions, the intermediate supports being hinges. This relation is based on the modal strain energy concept. Since frequency changes are relative small, to obtain natural frequencies with high resolution, a signal processing algorithm based on superposing of numerous spectra is also proposed, which overcomes the disadvantage of Fast Fourier Transform in the aspect of frequency resolution. Based on above-mentioned mathematical model and signal processing algorithm, the method of identifying cracks on multi-span beams is presented. To verify the accuracy of this identification method, experimental examples are conducted on a two-span structure. The results demonstrate that the method proposed in this paper can accurately identify the crack position and depth.