Research on Damage Identification of Suspension Bridge by Wavelet Analysis of the Strain Mode

2012 ◽  
Vol 193-194 ◽  
pp. 976-979 ◽  
Author(s):  
De Qing Guan ◽  
Qi Tang ◽  
Hong Wei Ying
Keyword(s):  
Wavelet Analysis ◽  
Damage Identification ◽  
Suspension Bridge ◽  
Lanczos Method ◽  
Suspension Bridges ◽  
Strain Mode ◽  
Analysis Theory ◽  
Damaged Zone ◽  
Bridge Damage ◽  
Object Of Study

The suspension bridge contained damage was made as the object of study. Three different damage conditions for suspension bridge were calculated(conditions 1, the left midspan contains a damaged zone, condition 2, the left end bay contains two damaged zone, condition 3, both sides midspan contains a damaged zone). Using the wavelet analysis theory, solving strain modal parameters of the suspension bridge with cracks by means of Lanczos method. Then the cracks location of the suspension bridges could be identified by the maximum of wavelet coefficients. It can be concluded that the method using wavelet analysis of strain mode is more accurate and more effective through the calculation and analysis of the suspension bridge damage identification. The method can be useful in the suspension bridge damage identification and diagnosis.

Damage Identification of Elastic Plate Based on Strain Mode Wavelet Analysis

2011 ◽  
Vol 71-78 ◽  
pp. 4078-4081
Author(s):  
De Qing Guan ◽  
Hong Wei Ying ◽  
Xiao Lin Zhong
Keyword(s):  
Finite Element Method ◽  
Wavelet Analysis ◽  
Elastic Plate ◽  
Damage Identification ◽  
The Finite Element Method ◽  
Strain Mode ◽  
Simply Supported ◽  
Analysis Theory ◽  
Mexican Hat Wavelet ◽  
Mexican Hat

By means of the wavelet analysis theory, the damage identification of elastic plate was studied. Adopted the finite element method to analyze the dynamic character of the plate and applied the method of Lanczos for calculating the strain mode, and the strain mode is analyzed by mexh wavelet (Mexican Hat wavelet). The location of the declining stiffness is identified by the place where maximum of wavelet coefficients appears. Therefore, this method is applied to the elastic damaged plate. Three types of damaged regions in rectangular simply supported plate are recognized, which indicates this method is effective and accurate. And this method has a certain value in the project application.

Research on Structural Damage Diagnosis Based on Strain Modal

2013 ◽  
Vol 438-439 ◽  
pp. 739-742
Author(s):  
Yi Na Zhang ◽  
Lei Cao
Keyword(s):  
Damage Detection ◽  
Cantilever Beam ◽  
Theoretical Basis ◽  
Structural Damage ◽  
Damage Identification ◽  
Damage Diagnosis ◽  
Strain Mode ◽  
Engineering Structure ◽  
Displacement Mode ◽  
Analysis Theory

The damage diagnosis theory and method of engineering structure is one of the hot issues concerned by the engineering circles at present. Based on the strain modal analysis theory, it expounds the connection among displacement mode, strain mode and curvature mode, with a heavy rubber as the material to make a cantilever beam, and establishing the different damage conditions of the cantilever beam, studying about dynamic structural damage identification under the incentive, which provides the theoretical basis and technical support for the research on damage detection of large engineering structure.

Thermal-Structure Coupling Damage Analysis for the Main Tower of Long-Span Suspension Bridge

2014 ◽  
Vol 1065-1069 ◽  
pp. 997-1001
Author(s):  
Bing Wang ◽  
Qiao Huang ◽  
Ping Ming Huang ◽  
Kui Hua Mei
Keyword(s):  
Thermal Structure ◽  
Moving Load ◽  
Damage Model ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Long Span ◽  
Propagation Behavior ◽  
Temperature Load ◽  
Bridge Damage ◽  
Damage Field

Long-span suspension bridges are usually affected by the ambient temperature and the moving load during the service life. The concrete tower has lots of visible cracks and other diseases. In this paper, Fengdu Yangtze River Highway Bridge with main span of 450m was taken for example. Based on the thermal structure coupling analysis for the main tower, the elastic damage model for concrete was introduced. The bridge damage field was calculated under different temperature load conditions, which illustrated the reasons of cracks objectively and effectively. The results can provide reference for the future analysis on crack propagation behavior of concrete structure under the temperature effects.

The Damage Identification of Multilayer Frame Structure Containing Sheet Crack by Wavelet Analysis

2012 ◽  
Vol 193-194 ◽  
pp. 1001-1004
Author(s):  
De Qing Guan ◽  
Liang Liu
Keyword(s):  
Wavelet Analysis ◽  
Structural Damage ◽  
Damage Identification ◽  
Frame Structure ◽  
The Finite Element Method ◽  
Damage Diagnosis ◽  
Structure Damage ◽  
Analysis Theory ◽  
Modulus Maxima ◽  
Calculation Analysis

In this paper, the multilayer frame structure containing sheet crack was researched. Based on wavelet analysis theory, the finite element method was applied to analyze the dynamic characteristics of structural damage. Established a method about the identification of containing sheet crack frame structure by modulus maxima of wavelet coefficients to determine the location of the crack, it verifies the validity of the method through calculation analysis of damage identification to a two layers of a cross frame structure containing sheet crack. The conclusions of this paper can be used for frame structure damage diagnosis application reference.

Research on Sheet Crack Identification of Frame Structure Using Wavelet Analysis

2011 ◽  
Vol 71-78 ◽  
pp. 4074-4077
Author(s):  
De Qing Guan ◽  
Xiao Lin Zhong ◽  
Hong Wei Ying
Keyword(s):  
Finite Element ◽  
Wavelet Transform ◽  
Wavelet Analysis ◽  
Structural Damage ◽  
Damage Identification ◽  
Frame Structure ◽  
Crack Identification ◽  
Wavelet Coefficients ◽  
Strain Mode ◽  
Plane Frame

This research presented the damage identification problem of frame structure using the wavelet transform of strain mode. Solving strain modal parameters of plane frames with cracks by means of the finite element theory, applying the gauss2 wavelet transform to analyze the stain mode of plane frame, and denoising the wavelet coefficients of the strain mode by db3 wavelet, then the location of crack of the plane frame could be identified by the maximum of wavelet coefficients after denoising. Taking one-layer plane frame as an example, this research gave the finite element model of framework with sheet crack (non-through surface crack and internal crack), calculated the strain mode of the structure, and identified the location of cracks by wavelet analysis of strain mode. Results show that this method is able to identify the damage of frame structure. Numerical calculation shows that the approach is effective. This paper provides a valuable reference of structural damage identification and diagnosis in engineering applications.

Control of Vibrations due to Moving Loads on Suspension Bridges

2006 ◽  
Vol 11 (3) ◽  
pp. 293-318 ◽  
Author(s):  
M. Zribi ◽  
N. B. Almutairi ◽  
M. Abdel-Rohman
Keyword(s):  
Bridge Deck ◽  
Suspension Bridge ◽  
Lyapunov Theory ◽  
Dynamic Responses ◽  
Suspension Bridges ◽  
Control Force ◽  
Moving Loads ◽  
Hydraulic Actuator ◽  
Long Span ◽  
Suspended Cables

The flexibility and low damping of the long span suspended cables in suspension bridges makes them prone to vibrations due to wind and moving loads which affect the dynamic responses of the suspended cables and the bridge deck. This paper investigates the control of vibrations of a suspension bridge due to a vertical load moving on the bridge deck with a constant speed. A vertical cable between the bridge deck and the suspended cables is used to install a hydraulic actuator able to generate an active control force on the bridge deck. Two control schemes are proposed to generate the control force needed to reduce the vertical vibrations in the suspended cables and in the bridge deck. The proposed controllers, whose design is based on Lyapunov theory, guarantee the asymptotic stability of the system. The MATLAB software is used to simulate the performance of the controlled system. The simulation results indicate that the proposed controllers work well. In addition, the performance of the system with the proposed controllers is compared to the performance of the system controlled with a velocity feedback controller.

Analysis and Test on Mechanical Properties of a Flexible Suspension Bridge

2013 ◽  
Vol 405-408 ◽  
pp. 1616-1622
Author(s):  
Guo Hui Cao ◽  
Jia Xing Hu ◽  
Kai Zhang ◽  
Min He
Keyword(s):  
Mechanical Properties ◽  
Suspension Bridge ◽  
Experimental Results ◽  
Suspension Bridges ◽  
Loading Test ◽  
Main Cable ◽  
Element Simulation ◽  
Static Loading Test ◽  
Geometric Nonlinear Analysis ◽  
Test Process

In order to research on mechanical properties of flexible suspension bridges, a geometric nonlinear analysis method was used to simulate on the experimental results, and carried on static loading test finally. In the loading test process, the deformations were measured in critical section of the suspension bridge, and displacement values of measured are compared with simulation values of the finite element simulation. Meanwhile the deformations of the main cable sag are observed under classification loading, the results show that the main cable sag increment is basically linear relationship with the increment of mid-span loading and tension from 3L/8 and 5L/8 to L/2 section, the main cable that increasing unit sag required mid-span loads and tension are gradually reduce in near L/4 and 3L/4 sections and gradually increase in near L/8 and 7L/8 sections and almost equal in near L/2, 3L/8 and 5L/8 sections. From the experimental results, the flexible suspension bridge possess good mechanical properties.

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