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.

scholarly journals Damage Identification Method of Box Girder Bridges Based on Distributed Long-Gauge Strain Influence Line under Moving Load

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 915
Author(s):  
Jing Yang ◽  
Peng Hou ◽  
Caiqian Yang ◽  
Ning Yang ◽  
Kefeng Li
Keyword(s):  
Working Conditions ◽  
Damage Identification ◽  
Strain Difference ◽  
Moving Load ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Influence Line ◽  
Damage Extent ◽  
The Difference

A new method was proposed for the damage identification of box girder bridges under moving load, wherein the difference of strain influence line (DSIL) was taken as an index to represent the long-gauge strain difference before and after damage. The damage identification theory based on long-gauge strain influence lines was derived for box girder bridges with shear lag effect under consideration, and a regularized index DSIL was proposed for the quantitative identifications of damage location and extent. A series of experiments were carried out to study the influences of speed, vehicle type, and vehicle weight on the damage identification, and the experimental data were obtained by long-gauge fiber Bragg grating strain sensors. Moreover, numerical simulations were performed to confirm the method. The experimental and numerical results show that the method can locate the damage accurately, and quantitatively identify the damage extent under different working conditions. The experimental damage extent is generally slightly higher than the theoretical, with an average identification error smaller than 5%. Additionally, the relative error of damage extent is smaller than 3% under different working conditions. Thus, the effectiveness of this method was verified.

A Novel Two-Stage Structural Damage Identification Method Based on Superposition of Modal Flexibility Curvature and Whale Optimization Algorithm

2021 ◽  
pp. 2150169
Author(s):  
Minshui Huang ◽  
Xihao Cheng ◽  
Zhigang Zhu ◽  
Jin Luo ◽  
Jianfeng Gu
Keyword(s):  
Optimization Algorithm ◽  
Damage Identification ◽  
Whale Optimization Algorithm ◽  
Two Stage ◽  
Simply Supported ◽  
Damage Location ◽  
Flexibility Matrix ◽  
Modal Flexibility ◽  
Whale Optimization ◽  
The Impact

A novel two-stage method is proposed to properly identify the location and severity of damage in plate structures. In the first stage, a superposition of modal flexibility curvature (SMFC) is adopted to locate the damage accurately, and the identification index of modal flexibility matrix is improved. The low-order modal parameters are used and a new column matrix is formed based on the modal flexibility matrix before and after the structure is damaged. The difference of modal flexibility matrix is obtained, which is used as a damage identification index. Meanwhile, based on SMFC, a method of weakening the “vicinity effect” is proposed to eliminate the impact of the surrounding elements to the damaged elements when damage identification is carried out for the plate-type structure. In the second stage, the objective function based on the flexibility matrix is constructed, and according to the damage location identified in the first stage, the actual damage severity is determined by the enhanced whale optimization algorithm (EWOA). In addition, the effects of 3% and 10% noise on damage location and severity estimation are also studied. By taking a simply supported beam and a four-side simply supported plate as examples, the results show that the method can accurately estimate the damage location and quantify the damage severity without noise. When considering noise, the increase of noise level will not affect the assessment of damage location, but the error of quantifying damage severity will increase. In addition, damage identification of a steel-concrete composite bridge (I-40 Bridge) under four damage cases is carried out, and the results show that the modified method can evaluate the damage location and quantify 5%–92% of the damage severity.

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.

scholarly journals Sealant Delamination Detection of Structural Sealant Glazing Systems Based on Driving-Point Accelerance

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Danguang Pan ◽  
Kun Jiang ◽  
Xichen Zhang ◽  
Ying Huang
Keyword(s):  
Damage Identification ◽  
Detection Method ◽  
The Finite Element Method ◽  
Acceleration Sensor ◽  
Glass Panel ◽  
Modal Assurance Criterion ◽  
Curtain Wall ◽  
Short Side ◽  
Glass Curtain Wall ◽  
The Difference

The structural sealant glazing system is widely used in glass curtain wall worldwide. However, due to the aging of the sealants, cracking may form along the sides of the glass. If the panel of curtain wall arises, delamination may occur and induce failure or loss of the system. In order to detect the delamination of the sealant, in this paper, a new vibration-based damage identification method is proposed by using the difference between the predamage and postdamage driving-point accelerance (DA). This detection method would require only one acceleration sensor on a glass panel and a rubber hammer, which operates very conveniently. When the rubber hammer taps the glass panel near the acceleration sensor, the glass curtain wall panel would generate acceleration response which can be measured by the acceleration sensor. The measured acceleration responses will be used to calculate the DA and lead to a new delamination index, called relative accumulative difference of DA, which will give indications on the potential delamination of the sealant. In addition, the influence of the acceleration sensor installation position was analysed by the finite element method, and the optimal sensor location was determined to be at the intersection of the long-side quarter and the short-side quarter. Nine cases on various delamination severities were identified by the new method, as well as the natural frequency reduction and modal assurance criterion. The laboratory experiments showed that the relative accumulative difference of DA is extremely sensitive to sealant delamination. Even if delamination severity was only 6.39%, the relative accumulative difference of DA would be larger than 18%. As the delamination of the sealant progresses, the relative accumulative difference of DA increases, resulting in an effective detection method for sealant delamination of the structural sealant glazing system. The fundamental frequency reduction is suitable to identify relatively large delamination, and the modal assurance criterion of higher modes is also sensitive to sealant delamination.

Damage Identification of the Arch Bridge Based on the Difference of Deflection with Moving Load

2014 ◽  
Vol 578-579 ◽  
pp. 1096-1100 ◽  
Author(s):  
Zhan Zhao ◽  
Zhen Hua Nie ◽  
Hong Wei Ma
Keyword(s):  
Damage Detection ◽  
Integral Method ◽  
Damage Identification ◽  
Moving Load ◽  
Detection Algorithm ◽  
Linear Functions ◽  
Arch Bridge ◽  
Damage Area ◽  
Bridge Structures ◽  
The Difference

A new damage identification method for arch bridge structures under a moving load based on the difference of deflection is presented. The function of the deflection at the mid span of the arch with the changing positions of the moving load is derived using the Moore integral method. It can be concluded from the results that when the moving load is in the area without damage, this target indicates to be linear functions with the cosine of an angle (θ) between moving load and horizontal. Nevertheless, this target is multinomial with the change of cosθ in the damage area. In order to validate the proposed damage detection algorithm, a steel arch modal is simulated, which is proved to be practicable in projects. The results indicate that the location and degree of single damage can be identified accurately.

scholarly journals Empirical method for structural damage location using dynamic analysis

2020 ◽  
Vol 13 (1) ◽  
pp. 19-31
Author(s):  
R. L. SILVA ◽  
L. M. TRAUTWEIN ◽  
C. S. BARBOSA ◽  
L. C. ALMEIDA ◽  
G. H. SIQUEIRA
Keyword(s):  
Finite Element ◽  
Structural Damage ◽  
Empirical Method ◽  
Finite Element Models ◽  
Simply Supported ◽  
Damage Location ◽  
Acceleration Amplitude ◽  
Modal Curvature ◽  
The Difference ◽  
Rubber Bearings

Abstract This paper presents the use of numerical model techniques for identification and damage location adopting the Modal Curvature Difference (MCD) method as reference for the analysis of a simply supported concrete structure. Then, an empirical formulation to detect damages in this structure is proposed. In this method, called Acceleration Summation Difference (ASD), the difference of acceleration amplitude between intact and damaged structures are calculated for concrete plates simply supported on rubber bearings. During the analyses, the finite element models were developed using SAP2000® software. The results obtained depicted that it is possible to determine the approximate position of one or more damages in the structure, with some restrictions, and the proposed ASD method presented good correlation to localize the position of single or multiple damages.

Numerical Studies on Wavelet-Based Crack Detection Based on Velocity Response of a Beam Subjecting to Moving Load

2013 ◽  
Vol 569-570 ◽  
pp. 854-859 ◽  
Author(s):  
Wei Wei Zhang ◽  
Jia Geng ◽  
Zi Long Zhao ◽  
Zhi Hua Wang
Keyword(s):  
Wavelet Transform ◽  
Damage Detection ◽  
Crack Detection ◽  
Moving Load ◽  
Noise Tolerance ◽  
Simply Supported Beam ◽  
Simply Supported ◽  
Damage Location ◽  
Numerical Studies ◽  
Velocity Response

In this paper, the possibility and validity of damage detection based on velocity response of a simply supported beam under the moving load are examined theoretically and numerically. It includes the following parts: First, the theoretic background of the beam vibration subjecting to moving load is briefly described. And then, the velocity responses of a simple supported beam are calculated by software Ansys. Using wavelet transform, the damage location can be identified successfully. At last, the effects of noise and load speed are discussed in detail. Numerical studies show the validity of the proposed method and a good noise tolerance using the velocity response.

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.

Damage Identification Research of Axial Vibration Modal Shape

2011 ◽  
Vol 250-253 ◽  
pp. 2515-2518
Author(s):  
Hai Wen Teng ◽  
Tao Wang ◽  
Ming Yu Su ◽  
Da Huo
Keyword(s):  
Damage Identification ◽  
Damage Index ◽  
Second Derivative ◽  
Axial Vibration ◽  
Modal Shape ◽  
Theoretical Derivation ◽  
Damage Location ◽  
Damage Degree ◽  
Vibration Modal ◽  
Identification Research

A new method taking the second derivative of low-level axial vibration modal shape as damage index is presented on the basis of theoretical derivation axial vibration differential equation and analytical solution of three kinds of support form. The index is very sensitive to damage location and damage degree. In addition, the effect of point number is analyzed and results showed that with a few points can still calibration damage well.

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