Space Rigid Frame Damage Identification Method Based on Modal Analysis

2013 ◽  
Vol 351-352 ◽  
pp. 1244-1248
Author(s):  
Hong Yu Jia ◽  
Peng Fei Yue ◽  
Xiao Fei Wang
Keyword(s):  
Modal Analysis ◽  
Structural Damage ◽  
Vibration Mode ◽  
Damage Identification ◽  
Three Dimensional ◽  
Frame Structure ◽  
Space Frame ◽  
First Order ◽  
Damage Location ◽  
Rigid Frame

Space frame structure of no damage and injury finite element models were established with ANSYS, and analyze 3D curvature mode as well three-dimensional vibration mode variety rate of the space rigid frame based on modal analysis. Curvature mode and three-dimensional vibration mode variety rate as the labeled amount was selected and applied to structural damage. The calculated results showed that the first-order curvature mode not only identify against single or multiple damage location, but also determine the initial degree of injury, and the axial curvature mode is better than the horizontal curvature mode for damage identification; The calculated results also showed that the variety rate of the first-order vibration mode can identify against damage location. Methods were provided by identifying the space frame structural damage of the curvature mode or three-dimensional vibration mode variety rate.

scholarly journals Residual Mode Vector-Based Structural Damage Identification with First-Order Modal Information

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Shuai Luo ◽  
Zhenxin Zhuang ◽  
Wei Wang ◽  
Ping Jiang
Keyword(s):  
Structural Damage ◽  
Damage Identification ◽  
Dynamic Properties ◽  
Good Condition ◽  
Quantitative Relationship ◽  
Service Condition ◽  
Damage Parameter ◽  
First Order ◽  
Damage Location ◽  
Structural Damage Identification

Damage identification based on the change of dynamic properties is an issue worthy of attention in structure safety assessment, nevertheless, only a small number of discontinuous members in existing structure are damaged under service condition, and the most remaining members are in good condition. According to this feather, we developed an effective damage location and situation assessment algorithm based on residual mode vector with the first mode information of targeted structure, which utilized the quantitative relationship between first natural modes of global structure with the change of the element stiffness. Firstly, the element damage location is determined with exploitation of the sparseness of element stiffness matrices based on the discontinuity of damaged members. Then, according to the distribution characteristics of the corresponding residual mode vector, the nodal equilibrium equation about the damage parameter is established based on the residual mode vector, and the damage coefficients of structural elements are evaluated with the proposed equations. Two numerical examples are given to verify the proposed algorithm. The results showed that the proposed damage identification method is consistent with the preset damage. It can even accurately identify large-degree damages. The proposed algorithm only required the first-order modal information of the target structures and held few requirements of analysis resource; hence when compared with existing methods, it has obvious advantages for structural damage identification.

Experimental Study of Damage Identification on Space Rigid Frame Structure

2012 ◽  
Vol 204-208 ◽  
pp. 2947-2950
Author(s):  
Zhi Hua Fang ◽  
Peng Fei Yue ◽  
Wei Na Zhang
Keyword(s):  
Damage Identification ◽  
High Sensitivity ◽  
Frame Structure ◽  
Ideal Space ◽  
Change Rate ◽  
Injury Site ◽  
Modal Data ◽  
Damage Location ◽  
Rigid Frame ◽  
The Difference

Damage identification method of space rigid frame was based on change rate with the difference of the first axial modal, which applied to the model of space rigid frame on experiment. With extracting the experimental modal data to calculate the change rate with difference of the first axial model, the result shown that the change rate with difference of first axial model increased significantly in the injury site, and could identify well the damage location of single or multiple injuries, which was an ideal space frame damage labeled amount because of high sensitivity, less work of measure and calculation.

Optimal Sensor Placement Algorithm for Structural Damage Identification

2020 ◽  
Vol 14 (1) ◽  
pp. 69-81
Author(s):  
C.H. Li ◽  
Q.W. Yang
Keyword(s):  
Structural Damage ◽  
Damage Identification ◽  
Sensor Placement ◽  
Optimization Procedure ◽  
Frame Structure ◽  
Truss Structures ◽  
Optimal Sensor Placement ◽  
Structural Damage Identification ◽  
Placement Algorithm ◽  
Sensor Locations

Background: Structural damage identification is a very important subject in the field of civil, mechanical and aerospace engineering according to recent patents. Optimal sensor placement is one of the key problems to be solved in structural damage identification. Methods: This paper presents a simple and convenient algorithm for optimizing sensor locations for structural damage identification. Unlike other algorithms found in the published papers, the optimization procedure of sensor placement is divided into two stages. The first stage is to determine the key parts in the whole structure by their contribution to the global flexibility perturbation. The second stage is to place sensors on the nodes associated with those key parts for monitoring possible damage more efficiently. With the sensor locations determined by the proposed optimization process, structural damage can be readily identified by using the incomplete modes yielded from these optimized sensor measurements. In addition, an Improved Ridge Estimate (IRE) technique is proposed in this study to effectively resist the data errors due to modal truncation and measurement noise. Two truss structures and a frame structure are used as examples to demonstrate the feasibility and efficiency of the presented algorithm. Results: From the numerical results, structural damages can be successfully detected by the proposed method using the partial modes yielded by the optimal measurement with 5% noise level. Conclusion: It has been shown that the proposed method is simple to implement and effective for structural damage identification.

Study on the Method of the Damage Identification for Frame Structure

2012 ◽  
Vol 204-208 ◽  
pp. 2824-2831
Author(s):  
You Fa Yang ◽  
Shuai Li ◽  
Ling Ling
Keyword(s):  
Analytical Solution ◽  
Iterative Algorithm ◽  
Taylor Series ◽  
Structural Damage ◽  
Damage Identification ◽  
Second Order ◽  
Bias Error ◽  
Dynamic Data ◽  
First Order ◽  
Sensitivity Equations

First order iterative algorithm, mixed iterative algorithm, structural damage identification using static and dynamic data were put forward. The first and second order sensitivity matrixes of modal parameters that respect to the damage member were derived, and the modal truncation error which produced during the derivation of modal mode sensitivity was improved. The first and second order sensitivity equations were established respectively based on the principle of Taylor series expansion. And the solving method of these sensitivity equations was studied. Mixed iterative algorithm took up the second order nonlinear analytical solution as the first substituting value, and then the first substituting value was modified based on the Taylor series bias error using the solution of the first order sensitivity equation. It showed that the mixed iterative algorithm in this paper had a better convergence and a faster iteration speed because the higher precision second order nonlinear analytical solution was adopted. Because the method using static and dynamic data combined the static information and dynamic information of the structure, it could react the inside information of the structure more comprehensively, the result of damage identification was more accurate and it would be adapted more widely.

scholarly journals Structural Damage Identification Based on the Minimum System Realization and Sensitivity Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-12
Author(s):  
W. R. Li ◽  
Y. F. Du ◽  
S. Y. Tang ◽  
L. J. Zhao
Keyword(s):  
Sensitivity Analysis ◽  
Damage Detection ◽  
Structural Damage ◽  
Damage Identification ◽  
Structural Information ◽  
Structural Response ◽  
Frame Structure ◽  
Structural Damage Detection ◽  
System Realization ◽  
Minimum System

On the basis of the thought that the minimum system realization plays the role as a coagulator of structural information and contains abundant information on the structure, this paper proposes a new method, which combines minimum system realization and sensitivity analysis, for structural damage detection. The structural damage detection procedure consists of three steps: (1) identifying the minimum system realization matrixes A, B, and R using the structural response data; (2) defining the mode vector, which is based on minimum system realization matrix, by introducing the concept of the measurement; (3) identifying the location and severity of the damage step by step by continuously rotating the mode vector. The proposed method was verified through a five-floor frame model. As demonstrated by numerical simulation, the proposed method based on the combination of the minimum realization system and sensitivity analysis is effective for the damage detection of frame structure. This method not only can detect the damage and quantify the damage severity, but also is not sensitive to the noise.

Application of BP Neural Network in Structural Damage Diagnosis of Bridge behind Abutment

2016 ◽  
Vol 847 ◽  
pp. 440-444 ◽  
Author(s):  
Yu Hui Zhang
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Bp Neural Network ◽  
Structural Damage ◽  
Damage Identification ◽  
Current Knowledge ◽  
Horizontal Displacement ◽  
Structural Deformation ◽  
Bp Network ◽  
Damage Location

BP neural network is introduced and applied to identify and diagnose both location and extent of bridge structural damage; static load tests and dynamic calculations are also made on bridge structural damage behind abutment. The key step of this method is to design a reasonably perfect BP network model. According to the current knowledge, three BP neural networks are designed with horizontal displacement rate and inherent frequency rate as damage identification indexes. The neural networks are used to identify the measurement of structure behind abutment and the calculation of damage location and extent, at the same time, they can also be used to compare and analyze the results. The test results show that: taking the two factors (static structural deformation rate and the change rate of natural frequency in dynamic response) as input vector, the BP neural network can accurately identify the damage location and extent, implying a promising perspective for future applications.

Modal Analysis for Swing-Arm of LED Die Bonder

2011 ◽  
Vol 422 ◽  
pp. 379-382
Author(s):  
Wei Chuang Quan ◽  
Mei Fa Huang ◽  
Zhi Yue Wang ◽  
Da Wei Zhang
Keyword(s):  
Modal Analysis ◽  
Vibration Mode ◽  
Three Dimensional ◽  
Element Model ◽  
Mode Shapes ◽  
Vibration Modes ◽  
Lead Frame ◽  
Swing Arm ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Led die bonder used for bond lead frame and chip is one of the key equipment of led production line. The swing-arm is an important component of led die bonder and its dynamic characteristics will directly affect the piece accuracy. At present, the accuracy and efficiency of led die bonder are limited because of the vibration of the swing-arm. In solving this problem, a three-dimensional finite-element model for swing-arm is built to provide analytical frequencies and vibration modes. Then the modal distribution and vibration mode shapes for swing-arm are obtained after analyzing the modal by ansys10.0. Finally the dynamics effects of this structure by modal frequency and vibration mode are analyzed. The modal analysis of structural would provide the reference to dynamics analysis and structural optimization for swing-arm in practical use.

The Research of Gantry Crane Girder Damage Problem by Modal Analysis Method

2014 ◽  
Vol 578-579 ◽  
pp. 872-876
Author(s):  
Xiao Peng Nie ◽  
Xin Gang Li ◽  
Hong Wei Fan ◽  
Ke Qin Ding ◽  
Li Bin Xu
Keyword(s):  
Numerical Simulation ◽  
Wavelet Analysis ◽  
Static Analysis ◽  
Damage Identification ◽  
Three Dimensional ◽  
Gantry Crane ◽  
Analysis Method ◽  
Ansys Software ◽  
Vibration Equation ◽  
Damage Location

most crane damage identification of the work has focused on the static analysis, that can't explain whether the crane has a damage or not by this way. So the paper explained the modal signal to analysis this problem , Used 300 tons gantry crane’s beam for background and ANSYS software as a tool was used for numerical simulation. The purpose is to find difference between the damage beam of the crane and health one,because if there was a damage on the beam , the formations and frequency will be changed. This theory of analysis is based on the vibration equation. In order to illustrate it better, the wavelet analysis method as a tool has been used ,in this case the signal was filtered, we can judge the damage location from the three dimensional curve. The basic aim of this paper is to arrive at a better way to judge the damage.Through the above analysis, the results proved the author's idea, identify structural’s damage basically, but it still need further research.

Study on Structural Damage Detection Using RBF Network

2014 ◽  
Vol 578-579 ◽  
pp. 1125-1128
Author(s):  
Jin Sheng Fan ◽  
Ying Yuan ◽  
Xiu Ling Cao
Keyword(s):  
Neural Network ◽  
Mode Shape ◽  
Structural Damage ◽  
Rbf Neural Network ◽  
Frame Structure ◽  
Structural Damage Detection ◽  
Element Analysis ◽  
Rbf Network ◽  
Damage Location ◽  
Trained Neural Network

Based on mode shape, a new parameter was put forward—mode shape curvature ratio, for detecting structure damages. And it was also the input vector of the RBF neural network. Then through finite element analysis and calculating, the training and forecasting samples were got for the network. The trained neural network can identify the damage location and degree of the frame structure. It proved that this method is simple and valid.

Research on Structural Damage Localization by Improved Curvature Method

2011 ◽  
Vol 255-260 ◽  
pp. 439-443
Author(s):  
Jun Chang ◽  
Yu Meng Wu
Keyword(s):  
Structural Damage ◽  
Damage Identification ◽  
Health Condition ◽  
Steel Beam ◽  
Damage Localization ◽  
Local Damage ◽  
Improved Method ◽  
Damage Location ◽  
Simple Support ◽  
Ideal Method

Damage identification is one of the main contents of structural health condition assessment. Curvature mode is an ideal method to identify structural damage location, with advantages of easy to be operated and sensitive to local damage, while the frequency is easy to test with high precision. An improved structural damage identification method is presented, which combines curvature and frequency. Finally, the improved method presented herein is verified by a simple support steel beam tested in laboratory. The results show that the improved method can effectively identify structural damage location.

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