Damage identification of 1D and 2D structures based on modal curvature analysis

2021 ◽  
pp. 547-555
Author(s):  
D. Dessi ◽  
F. Passacantilli
Keyword(s):  
Damage Identification ◽  
Curvature Analysis ◽  
Modal Curvature

scholarly journals Damage Identification Method of Beam Structure Based on Modal Curvature Utility Information Entropy

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Chang-Sheng Xiang ◽  
Ling-Yun Li ◽  
Yu Zhou ◽  
Zi Yuan
Keyword(s):  
Information Entropy ◽  
Damage Identification ◽  
Local Mode ◽  
Beam Structure ◽  
Damage State ◽  
Entropy Index ◽  
Damage Degree ◽  
Curvature Index ◽  
Modal Curvature ◽  
Utility Information

Generally, the damage of the structure will lead to the discontinuity of the local mode shape, which can be well reflected by the modal curvature of the structure, and the local information entropy of the beam structure will also change with the discontinuity of the mode. In this paper, based on the information entropy theory and combining the advantages of modal curvature index in damage identification of beam structure, the modal curvature utility information entropy index is proposed. The modal curvature curves of nondestructive structures were obtained by fitting the modal curvature curves of damage structures with the gapped smoothing technique to avoid dependence on the baseline data of nondestructive structures. The index comprehensively reflects the damage state of the structure by calculating mutual weight change matrix and the weight-probability coefficient. The performance of the new index was verified by the finite element simulation and model test of simply supported beam, respectively. The results show that the modal curvature utility information entropy index takes advantage of the modal curvature index which is sensitive to damage and can overcome its shortcomings effectively. The index proposed can identify the damage location and damage degree accurately and has certain noise immunity, which provides an effective damage identification indicator for beam structures.

Study on Box Girder Damage Identification of Cable-Stayed Bridges

2011 ◽  
Vol 101-102 ◽  
pp. 1156-1160
Author(s):  
Hua Wei Zhu ◽  
Hong Mou Wang ◽  
Wei Peng
Keyword(s):  
Damage Identification ◽  
Stress Index ◽  
Bending Stress ◽  
Box Girder ◽  
Cable Tension ◽  
Flexibility Matrix ◽  
Tension Index ◽  
Modal Flexibility ◽  
Curvature Index ◽  
Modal Curvature

A comparative study of the girder damage identification of Jintang Cable-stayed Bridge in Zhoushan Island-Land Project using the deflection index, the cable tension index, the beam bottom bending stress index, the modal curvature index and the modal flexibility matrix is introduced. By means of finite element method, a series of damage cases associated with the box girder are analyzed. The result shows that, for different damage types, the best effect of the girder damage identification is the modal curvature index, followed by the cable tension index, the beam bottom bending stress index is nearly of the same effect as the modal flexibility matrix index, and the worst is the deflection index.

scholarly journals Damage Identification of Bridge Based on Chebyshev Polynomial Fitting and Fuzzy Logic without Considering Baseline Model Parameters

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Yu-Bo Jiao ◽  
Han-Bing Liu ◽  
Yong-Chun Cheng ◽  
Ya-Feng Gong
Keyword(s):  
Fuzzy Logic ◽  
Chebyshev Polynomial ◽  
Damage Identification ◽  
Difference Approximation ◽  
Model Parameters ◽  
Polynomial Fitting ◽  
Fuzzy Logic Systems ◽  
Baseline Model ◽  
Modal Curvature ◽  
Logic Systems

The paper presents an effective approach for damage identification of bridge based on Chebyshev polynomial fitting and fuzzy logic systems without considering baseline model data. The modal curvature of damaged bridge can be obtained through central difference approximation based on displacement modal shape. Depending on the modal curvature of damaged structure, Chebyshev polynomial fitting is applied to acquire the curvature of undamaged one without considering baseline parameters. Therefore, modal curvature difference can be derived and used for damage localizing. Subsequently, the normalized modal curvature difference is treated as input variable of fuzzy logic systems for damage condition assessment. Numerical simulation on a simply supported bridge was carried out to demonstrate the feasibility of the proposed method.

Research Based on Modal Curvature and Wavelet Transform for Identifying Damage of Reticulated Shell Structures

2014 ◽  
Vol 501-504 ◽  
pp. 905-910
Author(s):  
Meng Hong Wang ◽  
Chen Meng Ji ◽  
Shan Shan Luo
Keyword(s):  
Wavelet Transform ◽  
Damage Identification ◽  
Shell Structures ◽  
Scaled Model ◽  
Transform Method ◽  
Stiffness Reduction ◽  
Modal Curvature ◽  
Transform Coefficients ◽  
The Difference ◽  
Reticulated Shell Structure

In this paper, a research is carried on to identify damage of reticulated shell structures based on the combination of modal curvature method and wavelets transform method. Take a scaled model of the reticulated shell structure as an example to analyze, the cross section of one member supposed to have a slight damage of stiffness reduction. In order to locate the damage, modal curvatures of the structure are taken as damage indexes to perform continuous wavelet transform. Results of the numerical analysis indicate that the difference of wavelet transform coefficients of modal curvature can be used to locate damage roughly, while the wavelet transform coefficients of modal curvature difference can be used to locate damage more precisely with easier and more reliable data processing. So it is clear that the damage identification based on modal curvature and wavelet transform is quite effective.

scholarly journals Non-Model Approach Based Damage Detection in RC Frame with Masonry Infill

Proceedings ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 56
Author(s):  
Himakshi Bhatia ◽  
Ajay Chourasia ◽  
Shilpa Pal
Keyword(s):  
Damage Detection ◽  
Damage Identification ◽  
Response Spectra ◽  
Mode Shapes ◽  
Rc Frame ◽  
Scaled Model ◽  
Masonry Infill ◽  
Building Research Institute ◽  
Time Histories ◽  
Modal Curvature

The paper focuses on real-time damage detection based on vibration studies carried out by the Central Building Research Institute (CBRI) structural health monitoring team. The experiment was performed on a 1:3 scaled model of a six- story reinforced concrete (RC) frame with masonry infill in the building dynamics laboratory of CBRI. The forward problem is attended by inducing step-by-step damage in infill to investigate the changes in dynamic response as a result of changes in the physical properties of the structure. Recorded time histories are processed for frequency response spectra (FRS) with fast fourier transform (FFT) and mode shapes are obtained. Changes in natural frequency and modal curvature for each of the five damage cases are analysed for damage detection and location in the structure. An algorithm for damage identification viz. curvature damage factor (CDF) approach is presented.

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