scholarly journals Robust Baseline-Free Damage Localization by Using Locally Perturbed Dynamic Equilibrium and Data Fusion Technique

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5964
Author(s):  
Shancheng Cao ◽  
Huajiang Ouyang ◽  
Chao Xu
Keyword(s):  
Data Fusion ◽  
Mode Shape ◽  
Structural Damage ◽  
Dynamic Equilibrium ◽  
Experimental Studies ◽  
Measurement Noise ◽  
Mode Shapes ◽  
Damage Localization ◽  
Shape Estimation ◽  
Fusion Approach

Mode shape-based structural damage identification methods have been widely investigated due to their good performances in damage localization. Nevertheless, the evaluation of mode shapes is severely affected by the measurement noise. Moreover, the conventional mode shape-based damage localization methods are normally proposed based on a certain mode and not effective for multi-damage localization. To tackle these problems, a novel damage localization approach is proposed based on locally perturbed dynamic equilibrium and data fusion approach. The main contributions cover three aspects. Firstly, a joint singular value decomposition technique is proposed to simultaneously decompose several power spectral density transmissibility matrices for robust mode shape estimation, which statistically deals better with the measurement noise than the traditional transmissibility-based methods. Secondly, with the identified mode shapes, an improved pseudo-excitation method is proposed to construct a baseline-free damage localization index by quantifying the locally damage perturbed dynamic equilibrium without the knowledge of material/structural properties. Thirdly, to circumvent the conflicting damage information in different modes and integrate it for robust damage localization, a data fusion scheme is developed, which performs better than the Bayesian fusion approach. Both numerical and experimental studies of cantilever beams with two cracks were conducted to validate the feasibility and effectiveness of the proposed damage localization method. It was found that the proposed method outperforms the traditional transmissibility-based methods in terms of localization accuracy and robustness.

The Use of Mode Shape Estimated from a Passing Vehicle for Structural Damage Localization and Quantification

2019 ◽  
Vol 19 (10) ◽  
pp. 1950124 ◽  
Author(s):  
Wen-Yu He ◽  
Jian He ◽  
Wei-Xin Ren
Keyword(s):  
Mode Shape ◽  
Structural Damage ◽  
Fem Simulation ◽  
Element Model ◽  
Mode Shapes ◽  
Damage Localization ◽  
Two Stage ◽  
Moving Vehicle ◽  
Satisfactory Precision ◽  
The Relationship

Mode shapes estimated from the vehicle responses are normally used to detect bridge damage efficiently for their high spatial resolution. However, an updated baseline finite element model (FEM) is normally required to quantify damages for such an approach. A two-stage damage detection procedure is presented for bridges by utilizing the mode shape estimated from a moving vehicle. Damage locations are first determined through a damage localization index (DLI) defined by regional mode shape curvature (RMSC). Then the relationship between the damage extents and the RMSC changes is investigated by FEM simulation. Finally, an equation set to quantify the single and multiple damages is deduced by combining the RMSCs and the relationship between the damage extents and the RMSC changes established by an un-updated FEM. Numerical and experimental examples are carried out to verify the validity and efficiency of the two-stage method. The results revealed that it can localize and quantify damages with satisfactory precision by using the response measured from one sensor only.

scholarly journals Ultrasonic Health Monitoring of Lithium-Ion Batteries

Electronics ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 751 ◽  
Author(s):  
Yi Wu ◽  
Youren Wang ◽  
Winco K. C. Yung ◽  
Michael Pecht
Keyword(s):  
Data Fusion ◽  
Experimental Studies ◽  
Lithium Ion ◽  
Battery Management ◽  
Early Failure ◽  
Battery Management Systems ◽  
Ultrasonic Sensing ◽  
Battery Degradation ◽  
Fusion Analysis ◽  
Fusion Approach

Because of the complex physiochemical nature of the lithium-ion battery, it is difficult to identify the internal changes that lead to battery degradation and failure. This study develops an ultrasonic sensing technique for monitoring the commercial lithium-ion pouch cells and demonstrates this technique through experimental studies. Data fusion analysis is implemented using the ultrasonic sensing data to construct a new battery health indicator, thus extending the capabilities of traditional battery management systems. The combination of the ultrasonic sensing and data fusion approach is validated and shown to be effective for degradation assessment as well as early failure indication.

scholarly journals Structural damage detection based on improved frequency change ratio

2019 ◽  
Vol 272 ◽  
pp. 01010
Author(s):  
Jian WANG ◽  
Huan JIN ◽  
Xiao MA ◽  
Bin ZHAO ◽  
Zhi YANG ◽  
...  
Keyword(s):  
Damage Detection ◽  
Health Monitoring ◽  
Structural Damage ◽  
Detection Method ◽  
Mode Shapes ◽  
Frequency Change ◽  
Damage Localization ◽  
Structural Damage Detection ◽  
Practical Application ◽  
Slight Damage

Frequency Change Ratio (FCR) based damage detection methodology for structural health monitoring (SHM) is analyzed in detail. The effectiveness of damage localization using FCR for some slight damage cases and worse ones are studied on an asymmetric planar truss numerically. Disadvantages of damage detection using FCR in practical application are found and the reasons for the cases are discussed. To conquer the disadvantages of FCR, an Improved Frequency Change Ratio (IFCR) based damage detection method which takes the changes of mode shapes into account is proposed. Verification is done in some damage cases and the results reveal that IFCR can identify the damage more efficiently. Noisy cases are considered to assess the robustness of IFCR and results indicate that the proposed method can work well when the noise is not severe.

scholarly journals Structural Damage Identification Based on Principal Curvatures of Mode Shape

2020 ◽  
Vol 25 (4) ◽  
pp. 566-576
Author(s):  
Rahim Gorgin ◽  
Ziping Wang
Keyword(s):  
Mode Shape ◽  
Structural Damage ◽  
Damage Identification ◽  
Mode Shapes ◽  
Principal Curvatures ◽  
Element Analysis ◽  
Identification Methods ◽  
Maximum Curvature ◽  
Curvature Variation ◽  
Identification And Characterization

This paper presents a procedure for damage identification and characterization on plates, based on the principal curvatures of their first mode shape. Each mode shape represents the displacement of the structure at its corresponding natural frequency. Since, variations in the geometry due to cracks or material property degradation, make changes in the mode shapes of the structure, such changes can be used for damage identification methods. The presented procedure only requires the first mode shape of the intact and damaged structure. It is shown that the principal curvatures of the surface defined by the first mode shape of the structure, are sensitive to damage and the maximum principal curvature can be used to highlight damages on the structure. The performance of the developed method is firstly evaluated using finite element analysis. To this aim, the procedure is applied to highlight both single and multi-damages in different locations of the plate with different boundary conditions. It is shown that the location of the maximum curvature variation coincides well with the location of damages and the amount of the maximum curvature change can be used as a parameter to describe damage severity. The accuracy of the proposed method is also experimentally verified by test on an aluminum plate and it is demonstrated that the proposed method remains effective even in experimental condition when only a limited number of measurements are available.

scholarly journals Investigation on Non-Linear Vibration Response of Cantilevered Thin Plates with Crack Using Electronic Speckle Pattern Interferometry

Proceedings ◽  
2018 ◽  
Vol 2 (8) ◽  
pp. 539
Author(s):  
Nan Tao ◽  
Yinhang Ma ◽  
Hanyang Jiang ◽  
Meiling Dai ◽  
Fujun Yang
Keyword(s):  
Mode Shape ◽  
Speckle Pattern ◽  
Experimental Studies ◽  
Forced Response ◽  
Thin Plates ◽  
Mode Shapes ◽  
Electronic Speckle Pattern Interferometry ◽  
Intact Specimen ◽  
Harmonic Resonance ◽  
Super Harmonic Resonance

The time-averaged electronic speckle pattern interferometry (ESPI) is employed to measure the frequencies and mode shapes of thin, cantilevered plates with root-slit. The first 12 order linear resonance frequency and mode shape of an intact cantilevered plate is determined by using FEM calculation. The dynamic response of the intact specimen forced by a PZT actuator is measured and its super-harmonic resonance of forced response is investigated experimentally. The results show that the principal mode shape of super-harmonic vibration is similar to its natural modal. In contrast to linear forcing vibration, the threshold of force for super-harmonic resonance is much higher than that of the former. In addition, linear free response of four cantilevered root-slit plates with variation length of slit are analyzed by applying the FEM calculation, and their responses of forcing vibration were measured by using the ESPI method. The validity and accuracy of the numerical prediction are confirmed through experimental studies. The present work shows that the ESPI technique can provide whole-field and real-time measurement for vibration analysis and can also be employed for validation of the FEM calculation.

Non-Model-Based Delamination Detection of Composite Plates Using Measured Mode Shapes

2017 ◽  
Author(s):  
Y. F. Xu ◽  
Da-Ming Chen ◽  
W. D. Zhu
Keyword(s):  
Mode Shape ◽  
Composite Plate ◽  
Damage Index ◽  
Laminated Composite ◽  
Composite Plates ◽  
Measurement Noise ◽  
Mode Shapes ◽  
Model Based ◽  
Damage Indices ◽  
Delamination Area

Delamination is one type of damage that frequently occurs in laminated composite structures, and identification of such damage has been a major research topic in the past few decades. This paper proposes an accurate non-model-based method for delamination identification of laminated composite plates. A weighted mode shape damage index is formulated using squared weighted difference between a measured mode shape of a composite plate with delamination and one from a polynomial that fits the measured mode shape of the composite plate with a proper order. Weighted mode shape damage indices associated with at least two measured mode shapes of the same mode are synthesized to formulate a synthetic mode shape damage index to exclude some false positive identification results due to measurement noise and error. An auxiliary mode shape damage index is proposed to further assist delamination identification, by which some false negative identification results can be excluded and edges of a delamination area can be accurately and completely identified. Numerical examples are presented to investigate effectiveness of the proposed method, and it is shown that edges of a delamination area in composite plates can be accurately and completely identified when measured mode shapes are contaminated by measurement noise and error.

Localizing and quantifying structural damage by means of a beetle swarm optimization algorithm

2020 ◽  
pp. 136943322095682
Author(s):  
Yufeng Jiang ◽  
Shuqing Wang ◽  
Yingchao Li
Keyword(s):  
Wind Turbine ◽  
Structural Damage ◽  
Experimental Studies ◽  
Measurement Data ◽  
Offshore Wind ◽  
Vibration Measurement ◽  
Mode Shapes ◽  
Offshore Wind Turbine ◽  
Swarm Optimization ◽  
Random Direction

An efficient meta-heuristic algorithm, named beetle swarm optimization (BSO), is proposed to localize and quantify structural damage using limited vibration measurement data. The beetle antennae search (BAS) algorithm that imitats a random walking mechanism in nature was recently developed to solve the optimization problem. However, the ratio of convergence of this algorithm significantly relys on the random direction and deviation for high-dimensional problems. To overcome this shortcoming, the BSO inspired by the swarm intelligence strategy is proposed. In the iterative search process of the BSO, each beetle swarm moves in a random direction like the BAS and the swarm of beetles is cognitive with the optimal one for the searching behavior. Consequently, the optimal one is updated step by step until a better beetle appears. To demonstrate the capability and robustness of the BSO, numerical and experimental studies using limited vibration measurement data of an offshore wind turbine structure are carried out for structural damage identification. An novel objective function is established by combining natural frequencies with mode shapes of the structure. The numerical results show that the BSO can accurately localize and quantify various types of damage even in a noise and temperature variations polluted environment. Moreover, it has higher accuracy and faster convergence speed than the BAS and the particle swarm optimization (PSO) algorithms. These promising performances could contribute to establishing a structural monitoring system for safety assurance of wind turbine structures.

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