Damage Identification Research of Cantilever Truss Based on the Principle of Strain Mode

2012 ◽  
Vol 226-228 ◽  
pp. 1432-1435
Author(s):  
Jun Hai Zhang ◽  
Nai Juan Du ◽  
Yue Guo Shen
Keyword(s):  
Structural Damage ◽  
Damage Identification ◽  
Damage Location ◽  
Strain Change ◽  
Before And After ◽  
Force Element ◽  
Damage Extent ◽  
Simulation Results ◽  
Modal Change ◽  
Identification Research

This paper presents a method converting the modal distance of the node into elemental strain based on the special characteristic of two-force element .The strain change before and after damage is applied to the damage identification. The change rule of the relative strain for the same location of the truss occur the various damage extent and the various location of the truss occur the same damage extent, respectively, is obtained according to the strain modal simulation using APDL language. The simulation results show that the strain modal change ratio is sensitive to the cantilever truss damage detection. The damage location and damage extent will be identified. It is an effective nodestructive test way to identify the cantilever truss structural damage.

Damage Identification of Plane Truss Structure According to Square Difference in Elemental Modal Strain

2015 ◽  
Vol 724 ◽  
pp. 22-27
Author(s):  
Wei Ran Liu ◽  
Shou Jun Du ◽  
Li Mei Zhang
Keyword(s):  
Damage Identification ◽  
Truss Structure ◽  
Truss Structures ◽  
Severe Damage ◽  
Damage Location ◽  
Damage Degree ◽  
Before And After ◽  
Simulation Results ◽  
Low Order

A method based on the square difference of elemental modal strain was proposed to determine the damage location and damage degree. The square difference of elemental modal strain was expressed damage before and after. Simulation results show that: this method is effective to locate the single, multiple damages and light, severe damage with low-order modal information. Damage degrees can be initially determined by the values of the square difference of damaged-element modal strain. Furthermore, the result also shows that this method can accurately identify the damage location of plane truss structures with noise.

scholarly journals Damage Identification of Multi-span Bridge Structure Based on the Recognition of Influence Line

2021 ◽  
Vol 233 ◽  
pp. 03002
Author(s):  
Zhang Yunkai ◽  
Xie Qingli ◽  
Li Guohua ◽  
Ye Yuntao
Keyword(s):  
Information Fusion ◽  
Damage Identification ◽  
Sensory Information ◽  
Bridge Structure ◽  
Damage Site ◽  
Damage Location ◽  
Influence Line ◽  
Before And After ◽  
Bridge Damage ◽  
Combining Information

The stress and deflection effects of the line changes before and after the bridge damage are used as indicators to evaluate the bridge damage and the initial damage site. Then a method of combining information is proposed to improve the accuracy of the damage site. Three-span continuous reinforced concrete was used in the analysis. According to the test, the effectiveness of damage identification based on the damage change of the influence line and the feasibility of the damage location method based on multi-sensory information fusion are confirmed.

Structural Multi-Damage Identification Based on Modal Strain Energy Equivalence Index Method

2014 ◽  
Vol 14 (07) ◽  
pp. 1450028 ◽  
Author(s):  
Hui Yong Guo ◽  
Zheng Liang Li
Keyword(s):  
Energy Dissipation ◽  
Structural Damage ◽  
Strain Energy ◽  
Damage Identification ◽  
Index Method ◽  
Modal Strain Energy ◽  
Energy Equivalence ◽  
Before And After ◽  
Accurate Expression ◽  
Equivalence Theory

In order to solve structural multi-damage identification problems, a damage detection method based on modal strain energy equivalence index (MSEEI) is presented. First, an accurate expression of modal strain energy (MSE) before and after damage occurs is given. Then, according to the energy equivalence theory that the change in MSE caused by the damage should be equivalent to the energy dissipation caused by the same damage, an energy equivalence equation is deduced. Finally, four roots of the energy equivalence equation are found and a MSEEI is obtained from the four roots. Simulation results demonstrate that the proposed MSEEI method can identify structural damage locations and extent with good accuracy. Identification precision of the proposed method is clearly better than that of the modal strain energy dissipation ratio index (MSEDRI) method.

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.

Damage Identification of a Beam-Like Structure Using Element Modal Strain Energies and Natural Frequencies

2011 ◽  
Vol 94-96 ◽  
pp. 718-723
Author(s):  
Jian Hua Zhao ◽  
Ling Zhang
Keyword(s):  
Natural Frequencies ◽  
Damage Identification ◽  
Identification Algorithm ◽  
Modal Strain Energy ◽  
Second Stage ◽  
Before And After ◽  
Damage Extent ◽  
Frequency Changes ◽  
Potential Damage ◽  
Actual Damage

A two-step damage identification method based on elemental modal strain energies and natural frequencies has been presented for a beam-like structure. In the first stage, this method makes use of the change of elemental modal strain energy before and after damage to locate the potential damage regions. And in the second stage, a damage identification algorithm based on the frequency changes is developed to calculate the damage extent and further determine the actual damage locations. The performance of the proposed method is numerically demonstrated by a simply supported beam with two damage cases. Results indicate that the method can identify the damage location and quantify the damage severity accurately in a beam-like structure.

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.

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.

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.

Detection Indicator of Structural Nondestructive Damage Based on Flexibility Curvature Difference Rate

2015 ◽  
Vol 744-746 ◽  
pp. 46-52 ◽  
Author(s):  
Chang Sheng Xiang ◽  
Yu Zhou ◽  
Sheng Kui Di ◽  
Li Xian Wang ◽  
Jian Shu Cheng
Keyword(s):  
Structural Damage ◽  
Damage Identification ◽  
Continuous Beam ◽  
Change Rate ◽  
Modal Frequency ◽  
Numerical Examples ◽  
Modal Flexibility ◽  
Structural Damage Identification ◽  
Before And After ◽  
Better Than

Applied to the structural damage identification, Modal Flexibility is better than the Modal Frequency and Modal Displacement, the indicators of Flexibility Curvature are effective and sensitive. This paper proposes a new detection indicator which is Flexibility Curvature Difference Rate (FCDR) that by using the change rate of diagonal elements of flexibility curvature difference when before and after damage. The numerical examples of a simple beam, a continuous beam and a frame with the damage conditions of the different positions and different degrees are used to verify FCDR. The result shows that FCDR can well identify the numerical examples damages, and sensitively diagnose the damage near the supports of beam and the nodes of framework.

Crack Damage Identification of Reinforced Concrete Simply Supported Beam Based on BP Neural Network

2012 ◽  
Vol 468-471 ◽  
pp. 738-741
Author(s):  
Xiao Ming Yang ◽  
Fu Li
Keyword(s):  
Neural Network ◽  
Reinforced Concrete ◽  
Bp Neural Network ◽  
Structural Damage ◽  
Damage Identification ◽  
Simply Supported Beam ◽  
Simply Supported ◽  
Before And After ◽  
Trained Neural Network ◽  
Application Prospects

Considering the good forecasting capability of BP neural network, a new crack damage identification method for reinforced concrete simply supported beam is proposed in this paper. After simulating the crack damage of a reinforced concrete simply supported beam, the natural frequency of the beam is chosen as the input parameters of the BP neural network. The data before and after damage of the simply supported beam are put into the trained neural network to judge the structural damage. The results demonstrate that the approach has a better application prospects in structural damage identification.

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