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.

Crack Identification of Frame Structure by Means of Wavelet Analysis of Strain Mode

2014 ◽  
Vol 638-640 ◽  
pp. 36-40
Author(s):  
Yan Huang
Keyword(s):  
Finite Element ◽  
Wavelet Transform ◽  
Damage Identification ◽  
Frame Structure ◽  
Crack Identification ◽  
Wavelet Coefficients ◽  
Strain Mode ◽  
Crack Location ◽  
Plane Frames ◽  
Plane Frame

Based on wavelet transform of strain mode, the damage identification of plane frame was studied in this paper. After 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, the crack location of the plane frame could be identified by the maximum of wavelet coefficients after denoising. Taking one-story plane frame for example, three finite element models, including a frame beam with a crack, each frame column with a crack, and each frame beam and column with a crack, were set up separately, then the above-mentioned method was applied to identify the location of the crack. The results show the method is effective, and it may be useful in damage identification and diagnosis in structures.

Crack Identification of Plane Frames Based on Wavelet Transform of Rotation Modes

2014 ◽  
Vol 578-579 ◽  
pp. 1224-1227
Author(s):  
Yan Huang
Keyword(s):  
Finite Element ◽  
Wavelet Transform ◽  
Wavelet Analysis ◽  
Damage Identification ◽  
Element Model ◽  
Crack Identification ◽  
Element Analysis ◽  
Rotation Mode ◽  
Plane Frames ◽  
Plane Frame

By means of the wavelet analysis theory, the damage identification of plane frame was studied. Based on the finite element analysis of modal parameters, the method using the wavelet analysis of rotation mode was proposed for plane frames crack identification, and the mexh wavelet transform was applied to analyze the rotation mode of plane frame, so the location of crack of the plane frame can be identified by the maximum of wavelet coefficients. Taking one-story plane frame for example, the finite element model, each frame beam and column with a crack, was seperately set up, and the above-mentioned method was applied to identify the location of the crack, and the results validate this method. Finally, compared with the result of the wavelet transform to analysis vibration mode and rotation mode, it can be concluded that the method using the wavelet analysis of rotation mode is more convenient and more effective. This method may be useful in damage identification and diagnosis in structures.

Crack Identification of Simple Beam via Wavelet Analysis of Vibration Modes

2013 ◽  
Vol 639-640 ◽  
pp. 1038-1041
Author(s):  
Yan Huang ◽  
Bo Lin Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Wavelet Analysis ◽  
Modal Parameters ◽  
Crack Identification ◽  
Vibration Modes ◽  
Wavelet Coefficients ◽  
Crack Location ◽  
Vibration Modal ◽  
Element Theory

Based on the finite element theory, a method is proposed for crack identification of simple beam via the wavelet analysis of vibration modal parameters. A cracked simple beam is simulated using finite element method, and its modal parameters, including first three-order vibration modes, are obtained. Then, these modal parameters are analyzed via mexh and db wavelets. The crack location of the simple beam is identified by the maximum of wavelet coefficients, which validates the proposed method. This research may be useful in crack identification of simple beam structures.

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.

Damage Identification of Space Truss Structure Based on Strain Modal and Wavelet Transform

2015 ◽  
Vol 744-746 ◽  
pp. 33-37 ◽  
Author(s):  
Wei Ran Liu ◽  
Qi Lian Li ◽  
Hong Liang Yue
Keyword(s):  
Wavelet Transform ◽  
Structural Damage ◽  
Damage Identification ◽  
Damage Index ◽  
Truss Structure ◽  
Truss Structures ◽  
Wavelet Coefficients ◽  
Modal Strain Energy ◽  
Space Truss ◽  
Space Truss Structure

Based on the characteristics of space truss structures, the concept of modal strain energy is introduced and square difference in elemental modal strain is presented. Through the square difference in elemental modal strain and wavelet transform, this paper presents a method for space truss structure damage recognition. The structural damage index is presented with the change of wavelet coefficients. Numerical simulation results show that: this method is effective to locate the single, multiple damages and light, severe damage with the first mode information. The preliminary tries for damage extent identification were made by the wavelet coefficients.

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.

scholarly journals Structural Damage Identification Based on Integrated Utilization of Inverse Finite Element Method and Pseudo-Excitation Approach

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 606
Author(s):  
Tengteng Li ◽  
Maosen Cao ◽  
Jianle Li ◽  
Lei Yang ◽  
Hao Xu ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Structural Damage ◽  
Damage Identification ◽  
Displacement Measurement ◽  
Engineering Practice ◽  
Position Measurement ◽  
Inverse Finite Element Method ◽  
Pseudo Excitation ◽  
Element Method

The attempt to integrate the applications of conventional structural deformation reconstruction strategies and vibration-based damage identification methods is made in this study, where, more specifically, the inverse finite element method (iFEM) and pseudo-excitation approach (PE) are combined for the first time, to give rise to a novel structural health monitoring (SHM) framework showing various advantages, particularly in aspects of enhanced adaptability and robustness. As the key component of the method, the inverse finite element method (iFEM) enables precise reconstruction of vibration displacements based on measured dynamic strains, which, as compared to displacement measurement, is much more adaptable to existing on-board SHM systems in engineering practice. The PE, on the other hand, is applied subsequently, relying on the reconstructed displacements for the identification of structural damage. Delamination zones in a carbon fibre reinforced plastic (CFRP) laminate are identified using the developed method. As demonstrated by the damage detection results, the iFEM-PE method possesses apparently improved accuracy and significantly enhanced noise immunity compared to the original PE approach depending on displacement measurement. Extensive parametric study is conducted to discuss the influence of a variety of factors on the effectiveness and accuracy of damage identification, including the influence of damage size and position, measurement density, sensor layout, vibration frequency and noise level. It is found that different factors are highly correlated and thus should be considered comprehensively to achieve optimal detection results. The application of the iFEM-PE method is extended to better adapt to the structural operational state, where multiple groups of vibration responses within a wide frequency band are used. Hybrid data fusion is applied to process the damage index (DI) constructed based on the multiple responses, leading to detection results capable of indicating delamination positions precisely.

scholarly journals A Super-Harmonic Feature Based Updating Method for Crack Identification in Rotors Using a Kriging Surrogate Model

2019 ◽  
Vol 9 (12) ◽  
pp. 2428 ◽  
Author(s):  
Zhiwen Lu ◽  
Yong Lv ◽  
Huajiang Ouyang
Keyword(s):  
Surrogate Model ◽  
Structural Damage ◽  
Damage Identification ◽  
Model Updating ◽  
Gaussian White Noise ◽  
Crack Identification ◽  
Breathing Crack ◽  
Kriging Surrogate Model ◽  
Nonlinear Characteristics ◽  
Practical Applications

Dynamic model updating based on finite element method (FEM) has been widely investigated for structural damage identification, especially for static structures. Despite the substantial advances in this method, the key issue still needs to be addressed to boost its efficiency in practical applications. This paper introduces the updating idea into crack identification for rotating rotors, which has been rarely addressed in the literature. To address the problem, a novel Kriging surrogate model-based FEM updating method is proposed for the breathing crack identification of rotors by using the super-harmonic nonlinear characteristics. In this method, the breathing crack induced nonlinear characteristics from two locations of the rotors are harnessed instead of the traditional linear damage features for more sensitive and accurate breathing crack identification. Moreover, a FEM of a two-disc rotor-bearing system with a response-dependent breathing crack is established, which is partly validated by experiments. In addition, the associated breathing crack induced nonlinear characteristics are investigated and used to construct the objective function of Kriging surrogate model. Finally, the feasibility and the effectiveness of the proposed method are verified by numerical experiments with Gaussian white noise contamination. Results demonstrate that the proposed method is effective, accurate, and robust for breathing crack identification in rotors and is promising for practical engineering applications.

Damage Identification of Arch Bridge Based on Curvature Mode Wavelet Analysis

2012 ◽  
Vol 166-169 ◽  
pp. 1176-1179
Author(s):  
De Qing Guan ◽  
Xiao Lin Zhong ◽  
Hong Wei Ying
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Wavelet Analysis ◽  
Damage Identification ◽  
Identification Problem ◽  
Haar Wavelet ◽  
Continuous Wavelet ◽  
The Finite Element Method ◽  
Mother Wavelet ◽  
Arch Bridge

Based on the curvature modal damage identification of wavelet analysis principle, the finite element method was applied to analyze the vibration characteristics of the damaged deck arch bridge. Take Haar wavelet as the mother wavelet, through the continuous wavelet transform of curvature mode and then identified the damaged position by the maximum of wavelet coefficients. analyze the damage identification problem under three different damaged conditions (condition 1: only the arch 1 contained one damaged location; condition 2: the arch 1 and the arch 2 contained one damaged location respectively; condition 3: the arch 1 contained two damaged locations and the arch 2 contained one damaged location).This paper provided a valuable reference of damage identification and diagnosis for arch bridge.

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