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.

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 Damage Identification of Ancient Timber Structure Based on Autocorrelation Function

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yanfang Hou ◽  
Weibing Hu ◽  
Xin Wang ◽  
Tingting Hou ◽  
Congli Sun
Keyword(s):  
Autocorrelation Function ◽  
Structural Damage ◽  
Damage Identification ◽  
Good Condition ◽  
Vibration Response ◽  
Value Change ◽  
Change Rate ◽  
Damage Location ◽  
Degree Of Damage ◽  
Peak Value

A damage location method for the autocorrelation peak value change rate based on the vibration response of a random vibration structure is established. To calculate the autocorrelation function of the vibration response of each measurement point, we transformed the maximum values into an autocorrelation peak vector. Under a good condition, the autocorrelation peak vector has a fixed shape; hence, it can be used as a basis for structural damage identification. The two adjacent measurement points with the largest change corresponding to the two nodes of the damage unit and the damage location are determined to calculate the change rate of the autocorrelation peak values between damaged and intact structures. When the degree of damage is 5%, the autocorrelation peak value change rate of the acceleration response on the two nodes of the damage unit is significantly greater than that of the other points, which can accurately determine the damage location, indicating that the damage location index constructed has good damage sensitivity. The damage location index can determine a single damage, as well as a double damage. The antinoise capability of the damage location index gradually improves with an increase in the degree of damage. At 45% degree of damage and signal-to-noise ratio (SNR) of 0 dB, the damage location index can still accurately determine the damage location, which has good antinoise interference capability. The Xi’an Bell Tower is used as a case study, and the feasibility of this method is verified, which provides a new method for the study of damage location of ancient timber structures.

Application of Taguchi Method to Identify Damage in Cantilever Beam

2003 ◽  
Author(s):  
Kye-Si Kwon ◽  
Rong-Ming Lin
Keyword(s):  
Taguchi Method ◽  
Cantilever Beam ◽  
Damage Identification ◽  
Fe Model ◽  
Random Errors ◽  
Reasonable Accuracy ◽  
Modal Data ◽  
Identification Technique ◽  
The Difference ◽  
Main Effects

A robust damage identification technique is presented such that the location and severity of damages can be identified in presence of random errors in measured data as well as systematic errors in analytical model. In order to identify damage efficiently, the concept of design of experiment using orthogonal array is used for screening main effects of each parameter which corresponds to possible damage location in FE model. Then, Taguchi method, which has been widely used for robust design in industry, is applied to the optimization of the objective function, which is defined by the difference between measured and analytical modal data, by updating the parameters in analytical FE model in an iterative way. The numerical simulation of cantilever beam shows that various types of damages can be identified effectively with reasonable accuracy.

Damage Identification Method Research Based on the Change Rate of Strain Mode

2012 ◽  
Vol 166-169 ◽  
pp. 1267-1271
Author(s):  
Shu Wei Wang ◽  
Ying Ming Zhou
Keyword(s):  
Damage Identification ◽  
True Strain ◽  
Frame Structure ◽  
Reinforced Concrete Frame ◽  
Change Rate ◽  
Strain Mode ◽  
Concrete Frame ◽  
Identification Method ◽  
Reinforced Concrete Frame Structure ◽  
Before And After

Damage identification method based on the change rate of strain mode is studied in this paper. Reinforced concrete frame structure as a researching object, true strain mode of structure is obtained by external excitation, graphics of strain mode and change rate of strain mode of the frame structure before and after the damage are established and analyzed. The results show that the change rate of strain mode is sensitive to the damage, and the location and extent of the damage can be judged through this method.

Damage Detection of a Substructure Based on Response Reconstruction in Frequency Domain

2013 ◽  
Vol 569-570 ◽  
pp. 823-830 ◽  
Author(s):  
Jun Li ◽  
Siu Seong Law ◽  
Yong Ding
Keyword(s):  
Frequency Domain ◽  
Damage Identification ◽  
Structural Response ◽  
Element Model ◽  
Frame Structure ◽  
Identification Algorithm ◽  
Response Reconstruction ◽  
The Difference ◽  
And Performance ◽  
Response Vector

A substructural damage identification approach based on structural response reconstruction in frequency domain is presented. The response reconstruction is based on transforming the measured responses into responses at other locations with the transmissibility matrix and then the relationship between two sets of response vectors is formulated. The damage identification is conducted by minimizing the difference between a measured response vector and the reconstructed response vector. Measured acceleration responses from the damaged substructure and the finite element model of the intact substructure only are required in the identification algorithm. A dynamic response sensitivity-based method with the adaptive Tikhonov regularization technique is adopted for the damage identification with improved results from noisy measurements. A seven-storey frame structure is taken as an example to illustrate the effectiveness and performance of the proposed approach.

Study of damage identification for bridges based on deep belief network

2020 ◽  
Vol 23 (8) ◽  
pp. 1562-1572
Author(s):  
Qi Guo ◽  
Lei Feng ◽  
Ruyi Zhang ◽  
Haijun Yin
Keyword(s):  
Neural Network ◽  
Damage Identification ◽  
Damage Index ◽  
Back Propagation ◽  
Back Propagation Neural Network ◽  
Deep Belief Network ◽  
Belief Network ◽  
Modal Data ◽  
Damage Location ◽  
Incomplete Measurement

To solve the problem of poor anti-noise ability faced by traditional pattern recognition methods in damage identification field, a bridge damage identification method based on deep belief network was proposed. Taken the modal curvature difference as the damage index, three restricted Boltzmann machines were constructed for pre-training. Then, the Softmax classifier and neural network were used to identify the damage location and degree under the environmental cases of no noise, weak noise, and strong noise, respectively. Subsequently, the influence of incomplete measurement modal data on the method was studied. Finally, damage identification based on deep belief network was implemented to a continuous beam bridge and compared with that of the back propagation neural network. The results showed that the proposed method could be highly effective not only on damage location but also on degree identification. Compared with back propagation neural network, deep belief network method may possess better identification ability and stronger anti-noise ability. It also demonstrates good identification effect under the condition of incomplete measurement modal data.

Study on Damage Identification of the Simply Supported Beam Employ the Difference of Deflection Influence Line under Symmetrically Load

2012 ◽  
Vol 166-169 ◽  
pp. 1254-1257 ◽  
Author(s):  
Yunshuai Liu ◽  
Xiaoqin Wang ◽  
Feng Xi Zhou
Keyword(s):  
Damage Identification ◽  
Detection Method ◽  
Moving Load ◽  
The Other ◽  
Theoretical Derivation ◽  
Simply Supported ◽  
Damage Location ◽  
Influence Line ◽  
Element Simulation ◽  
The Difference

In order to solve the problem that it need too large number of sensors and data of undamaged structure, the method of damage detection employ difference of deflection influence line under symmetrically load is proposed. theoretical derivation and finite element simulation shows that the curvature of the influence line is less than zero when the moving load is located in the damage region and it is no less than zero when the moving load is located in the other regions. so the damage location and extent can be detected by using this method, furthermore, this detection method is suitable for not only single damage but also multi damage.

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.

Sparse damage detection via the elastic net method using modal data

2021 ◽  
pp. 147592172110219
Author(s):  
Rongrong Hou ◽  
Xiaoyou Wang ◽  
Yong Xia
Keyword(s):  
Damage Detection ◽  
Structural Damage ◽  
Damage Identification ◽  
Measurement Data ◽  
Elastic Net ◽  
Sensitivity Matrix ◽  
Regularization Technique ◽  
Modal Data ◽  
Regularization Techniques ◽  
Net Method

The l1 regularization technique has been developed for damage detection by utilizing the sparsity feature of structural damage. However, the sensitivity matrix in the damage identification exhibits a strong correlation structure, which does not suffice the independency criteria of the l1 regularization technique. This study employs the elastic net method to solve the problem by combining the l1 and l2 regularization techniques. Moreover, the proposed method enables the grouped structural damage being identified simultaneously, whereas the l1 regularization cannot. A numerical cantilever beam and an experimental three-story frame are utilized to demonstrate the effectiveness of the proposed method. The results showed that the proposed method is able to accurately locate and quantify the single and multiple damages, even when the number of measurement data is much less than the number of elements. In particular, the present elastic net technique can detect the grouped damaged elements accurately, whilst the l1 regularization method cannot.

scholarly journals Wavelet Energy Accumulation Method Applied on the Rio Papaloapan Bridge for Damage Identification

Mathematics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 422
Author(s):  
Jose M. Machorro-Lopez ◽  
Juan P. Amezquita-Sanchez ◽  
Martin Valtierra-Rodriguez ◽  
Francisco J. Carrion-Viramontes ◽  
Juan A. Quintana-Rodriguez ◽  
...  
Keyword(s):  
Bridge Deck ◽  
Damage Identification ◽  
Area Under The Curve ◽  
Economic Losses ◽  
Civil Structures ◽  
Vibration Signals ◽  
Energy Accumulation ◽  
Damage Location ◽  
Wavelet Energy ◽  
Accumulation Method

Large civil structures such as bridges must be permanently monitored to ensure integrity and avoid collapses due to damage resulting in devastating human fatalities and economic losses. In this article, a wavelet-based method called the Wavelet Energy Accumulation Method (WEAM) is developed in order to detect, locate and quantify damage in vehicular bridges. The WEAM consists of measuring the vibration signals on different points along the bridge while a vehicle crosses it, then those signals and the corresponding ones of the healthy bridge are subtracted and the Continuous Wavelet Transform (CWT) is applied on both, the healthy and the subtracted signals, to obtain the corresponding diagrams, which provide a clue about where the damage is located; then, the border effects must be eliminated. Finally, the Wavelet Energy (WE) is obtained by calculating the area under the curve along the selected range of scale for each point of the bridge deck. The energy of a healthy bridge is low and flat, whereas for a damaged bridge there is a WE accumulation at the damage location. The Rio Papaloapan Bridge (RPB) is considered for this research and the results obtained numerically and experimentally are very promissory to apply this method and avoid accidents.

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