scholarly journals Damage Identification Method Using Additional Virtual Mass Based on Damage Sparsity

2021 ◽  
Vol 11 (21) ◽  
pp. 10152
Author(s):  
Qingxia Zhang ◽  
Dengzheng Xu ◽  
Jilin Hou ◽  
Łukasz Jankowski ◽  
Haiyan Wang
Keyword(s):  
Structural Damage ◽  
Damage Identification ◽  
Selection Process ◽  
Identification Accuracy ◽  
Original Structure ◽  
Virtual Mass ◽  
Deformation Method ◽  
Damage Scenario ◽  
Identification Method ◽  
L2 Norm

Damage identification methods based on structural modal parameters are influenced by the structure form, number of measuring sensors and noise, resulting in insufficient modal data and low damage identification accuracy. The additional virtual mass method introduced in this study is based on the virtual deformation method for deriving the frequency-domain response equation of the virtual structure and identify its mode to expand the modal information of the original structure. Based on the initial condition assumption that the structural damage was sparse, the damage identification method based on sparsity with l1 and l2 norm of the damage-factor variation and the orthogonal matching pursuit (OMP) method based on the l0 norm were introduced. According to the characteristics of the additional virtual mass method, an improved OMP method (IOMP) was developed to improve the localization of optimal solution determined using the OMP method and the damage substructure selection process, analyze the damage in the entire structure globally, and improve damage identification accuracy. The accuracy and robustness of each damage identification method for multi-damage scenario were analyzed and verified through simulation and experiment.

Structural Damage Identification Method Based On Transmissibility in Time Domain

2021 ◽  
Author(s):  
Yunfeng Zou ◽  
Xuandong Lu ◽  
Jinsong Yang ◽  
Xuhui He ◽  
Tiantian Wang
Keyword(s):  
Time Domain ◽  
Structural Damage ◽  
High Efficiency ◽  
Damage Identification ◽  
Identification Accuracy ◽  
Reconstruction Method ◽  
Fe Model ◽  
Time Frequency ◽  
Identification Method ◽  
Structural Damage Identification

Abstract Structural damage identification technology is of great significance to improve the reliability and safety of civil structures and has attracted much attention in the study of structural health monitoring. In this paper, a novelty structural damage identification method based on the transmissibility in time domain is proposed. The method takes the discrepancy of transmissibility of structure response in time domain before and after damage as the basis of finite element model modification. The damage location and damage degree are obtained through iteration by minimizing the difference between the measurements at gauge locations and the reconstruction response extrapolated by FE model. Taking the advantage of the response reconstruction method based on empirical mode decomposition, the damage information is possible to obtain in the absence of prior knowledge on external excitation information. Moreover, this method is carried out in the time domain, without the need to identify the modal parameters and perform time-frequency analysis, which simplicity ensures the high efficiency of damage identification. The effectiveness and accuracy of the proposed method are studied by simulation, including reconstruction error and measurement noise. The identification results demonstrate that the proposed structural damage identification method improves the calculation effectiveness considerably and ensures the identification accuracy.

scholarly journals A Mahalanobis Distance Cumulant-Based Structural Damage Identification Method with IMFs and Fitting Residual of SHM Measurements

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Chuang Chen ◽  
Yinhui Wang ◽  
Tao Wang ◽  
Xiaoyan Yang
Keyword(s):  
Mahalanobis Distance ◽  
Structural Damage ◽  
Damage Identification ◽  
Feature Vector ◽  
Recursive Algorithm ◽  
Intrinsic Mode Functions ◽  
Data Set ◽  
Identification Method ◽  
Structural Damage Identification ◽  
Emd Method

Data-driven damage identification based on measurements of the structural health monitoring (SHM) system is a hot issue. In this study, based on the intrinsic mode functions (IMFs) decomposed by the empirical mode decomposition (EMD) method and the trend term fitting residual of measured data, a structural damage identification method based on Mahalanobis distance cumulant (MDC) was proposed. The damage feature vector is composed of the squared MDC values and is calculated by the segmentation data set. It makes the changes of monitoring points caused by damage accumulate as “amplification effect,” so as to obtain more damage information. The calculation method of the damage feature vector and the damage identification procedure were given. A mass-spring system with four mass points and four springs was used to simulate the damage cases. The results showed that the damage feature vector MDC can effectively identify the occurrence and location of the damage. The dynamic measurements of a prestress concrete continuous box-girder bridge were used for decomposing into IMFs and the trend term by the EMD method and the recursive algorithm autoregressive-moving average with the exogenous inputs (RARMX) method, which were used for fitting the trend term and to obtain the fitting residual. By using the first n-order IMFs and the fitting residual as the clusters for damage identification, the effectiveness of the method is also shown.

Non-model-based damage identification of plates using measured mode shapes

2016 ◽  
Vol 16 (1) ◽  
pp. 3-23 ◽  
Author(s):  
Yongfeng Xu ◽  
Weidong Zhu
Keyword(s):  
Structural Damage ◽  
Damage Identification ◽  
Damage Index ◽  
Thickness Reduction ◽  
Aluminum Plate ◽  
Mode Shapes ◽  
Identification Method ◽  
Model Based

Mode shapes (MSs) have been extensively used to detect structural damage. This paper presents a new non-model-based damage identification method that uses measured MSs to identify damage in plates. A MS damage index (MSDI) is proposed to identify damage near regions with consistently high values of MSDIs associated with MSs of different modes. A MS of a pseudo-undamaged plate can be constructed for damage identification using a polynomial of a properly determined order that fits the corresponding MS of a damaged plate, if the associated undamaged plate is geometrically smooth and made of materials that have no stiffness and mass discontinuities. It is shown that comparing a MS of a damaged plate with that of a pseudo-undamaged plate is better for damage identification than with that of an undamaged plate. Effectiveness and robustness of the proposed method for identifying damage of different positions and areas are numerically investigated using different MSs; effects of crucial factors that determine effectiveness of the proposed method are also numerically investigated. Damage in the form of a machined thickness reduction area was introduced to an aluminum plate; it was successfully identified by the proposed method using measured MSs of the damaged plate.

Local Mass Addition and Data Fusion for Structural Damage Identification Using Approximate Models

2020 ◽  
Vol 20 (11) ◽  
pp. 2050124
Author(s):  
Jilin Hou ◽  
Zhenkun Li ◽  
Qingxia Zhang ◽  
Łukasz Jankowski ◽  
Haibin Zhang
Keyword(s):  
Data Fusion ◽  
Objective Function ◽  
Structural Damage ◽  
Damage Identification ◽  
Structural Parameters ◽  
Identification Accuracy ◽  
Fe Model ◽  
Local Damage ◽  
Approximate Models ◽  
Structural Damage Identification

In practical civil engineering, structural damage identification is difficult to implement due to the shortage of measured modal information and the influence of noise. Furthermore, typical damage identification methods generally rely on a precise Finite Element (FE) model of the monitored structure. Pointwise mass alterations of the structure can effectively improve the quantity and sensitivity of the measured data, while the data fusion methods can adequately utilize various kinds of data and identification results. This paper proposes a damage identification method that requires only approximate FE models and combines the advantages of pointwise mass additions and data fusion. First, an additional mass is placed at different positions throughout the structure to collect the dynamic response and obtain the corresponding modal information. The resulting relation between natural frequencies and the position of the added mass is sensitive to local damage, and it is thus utilized to form a new objective function based on the modal assurance criterion (MAC) and [Formula: see text]-based sparsity promotion. The proposed objective function is mostly insensitive to global structural parameters, but remains sensitive to local damage. Several approximate FE models are then established and separately used to identify the damage of the structure, and then the Dempster–Shafer method of data fusion is applied to fuse the results from all the approximate models. Finally, fractional data fusion is proposed to combine the results according to the parametric probability distribution of the approximate FE models, which allows the natural weight of each approximate model to be determined for the fusion process. Such an approach circumvents the need for a precise FE model, which is usually not easy to obtain in real application, and thus enhances the practical applicability of the proposed method, while maintaining the damage identification accuracy. The proposed approach is verified numerically and experimentally. Numerical simulations of a simply supported beam and a long-span bridge confirm that it can be used for damage identification, including a single damage and multiple damages, with a high accuracy. Finally, an experiment of a cantilever beam is successfully performed.

The Feasibility Study of Vibration Transmissibility Applied to Structure Damage Identification

2013 ◽  
Vol 347-350 ◽  
pp. 107-110
Author(s):  
Sen Wu ◽  
Bin Wang ◽  
Hai Hua Zhang
Keyword(s):  
Numerical Simulation ◽  
Cantilever Beam ◽  
Feasibility Study ◽  
Structural Damage ◽  
Simulation Experiment ◽  
Damage Identification ◽  
Structure Damage ◽  
Damage Location ◽  
Identification Method ◽  
Vibration Transmissibility

In view of the defects of the traditional damage identification method based on vibration,the damage identification method based on vibration transmissibility is put forward. The feasibility of the vibration transmissibility applied to structural damage identification is analyzed by the numerical simulation experiment of a cantilever beam, the analysis results show that, vibration transmissibility contains the structure damage severity, damage location and other useful information, and all the information is favor of the damage identification.

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