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.

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 Location Identification of Truss Structure Based on Strain Modal Method

2014 ◽  
Vol 919-921 ◽  
pp. 51-57 ◽  
Author(s):  
Bei Dou Ding ◽  
Ming Tang ◽  
Ya Nan Shang
Keyword(s):  
Damage Identification ◽  
Truss Structure ◽  
Truss Structures ◽  
Fatigue Load ◽  
Structural Element ◽  
Vibration Displacement ◽  
Damage Location ◽  
Location Identification ◽  
Damage Alarming ◽  
Modal Method

Due to the fatigue load and bad corrosion environment, truss structure in service will form the damage accumulation, damage detection of potentially damaged elements of truss structures is a challenging topic. According to the element stress characteristics of truss structure, structural element strain mode mainly based on the vibration displacement is derived, the change of elemental strain modal is proposed as the dynamic indicator for damage location identification of truss structure. Based on the numerical simulation study of the actual truss structure indicates that, the loworder elemental strain modal method is not only sensitive to damage identification of chord element and web element of truss structure, but also is effective to locate the damage of different position, and is suitable for damage alarming of truss structure in service.

A Two Step Damage Prognosis Method for Beam-Like Truss Structures

2014 ◽  
Vol 578-579 ◽  
pp. 1092-1095
Author(s):  
Hao Kai Jia ◽  
Ling Yu
Keyword(s):  
Finite Element Method ◽  
Strain Energy ◽  
Truss Structure ◽  
Truss Structures ◽  
Second Step ◽  
The Finite Element Method ◽  
Modal Strain Energy ◽  
Damage Prognosis ◽  
Modal Curvature ◽  
Simulation Results

In this study, a two step damage prognosis method is proposed for beam-like truss structures via combining modal curvature change (MCC) with modal strain energy change ratio (MSECR). Changes in the modal curvature and the elemental strain energy are selected as the indicator of damage prognosis. Different damage elements with different damage degrees are simulated. In the first step, the finite element method is used to model a beam-like truss structure and the displacement modes are got. The damage region is estimated by the MCC of top and bottom chords of a beam-like truss structure. In the second step, the elemental MSECR in the damage region is calculated and the maximum MSECR element is deemed as the damage element. The simulation results show that this method can accurately locate the damage in the beam-like truss structure.

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.

Damage Detection Method Based on Fractal Correlation Dimension for Steel Truss Structure

2014 ◽  
Vol 578-579 ◽  
pp. 1228-1232
Author(s):  
Shou Jun Du ◽  
Li Bin Shi ◽  
Li Mei Zhang
Keyword(s):  
Correlation Dimension ◽  
Detection Method ◽  
Fractal Theory ◽  
Sudden Change ◽  
Truss Structure ◽  
Structural Vibration ◽  
Damage Location ◽  
Damage Degree ◽  
Steel Truss ◽  
Fractal Correlation Dimension

Damage of steel truss structure can be determined by the sudden change of correlation dimension which was obtained from the structural vibration response through fractal theory. The streel truss structure was as exampled to verify this method. The results show that: this method can determine the damage location of the structure whether single damage or multi damage and can preliminarily judge the damage degree.

scholarly journals Clustering Elements of Truss Structures for Damage Identification by CBO

2020 ◽  
Author(s):  
Mohammad Hosein Talebpour ◽  
Younes Goudarzi ◽  
Mehrdad Sharifnezhad
Keyword(s):  
Damage Detection ◽  
Damage Identification ◽  
Dynamic Properties ◽  
Heuristic Method ◽  
Search Space ◽  
Truss Structures ◽  
Local Optimum ◽  
Structural Elements ◽  
Modal Strain Energy ◽  
Damage Location

The number of structural elements plays a significant role in detecting damage location and severity; such methods have sometimes failed to provide correct solutions due to the entrapment of damage detection algorithms in the local optimum. To resolve this problem, this study proposed the simultaneous use of mathematical and statistical methods to narrow down the search space. To this end, a two-step damage detection method was proposed. In the first step, the structural elements were initially divided into different clusters using the k-means method. Subsequently, the possibly damaged elements of each cluster were identified. In the second step, the elements selected in the first step were placed in a new set, and a process was applied to identify their respective damage location and severity. Thus, the proposed method reduced the search space as well as the possibility of entrapment in the local optimum. Other advantages of the proposed method include the use of fewer dynamic properties. Accordingly, by narrowing down the search space and the dimensions of the system for governing equations, the proposed method could significantly increase the chance of obtaining favorable results in structures with many elements and those with few vibration modes. A meta-heuristic method, called the colliding bodies optimization (CBO), was used in the proposed damage detection optimization algorithm. The optimization problem was based on the modal strain energy equations. According to the results, the proposed method was able to detect the location and severity of damage, even at its slightest percentage.

A Method of Damage Identification for Shear Buildings

2012 ◽  
Vol 166-169 ◽  
pp. 1484-1488
Author(s):  
Feng Li ◽  
Ju Lin Wang
Keyword(s):  
Numerical Simulation ◽  
Present Method ◽  
Taylor Expansion ◽  
Damage Identification ◽  
Linear Equations ◽  
Damage Location ◽  
Identification Method ◽  
Before And After ◽  
Shear Buildings ◽  
High Measure

Based on the easy testability and high measure precision of structural frequency, a damage identification method for shear buildings is presented. With frequency being regarded as the function of damage parameters, the linear equations with damage parameters as unknowns can be constructed via Taylor expansion. The equations are solved to locate the whole damage location and quantify the severity of the damage. Furthermore, the iteration-self modification is proposed to improve the accuracy of damage identification greatly. The data used in the method include frequency before and after damage. A numerical simulation example using a three-storey sheer structure is given to validate the present method.

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.

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.

Damage Identification of a Cantilever Beam with a Breathing Crack Based on Instantaneous Frequency

2011 ◽  
Vol 368-373 ◽  
pp. 2169-2174
Author(s):  
Qiu Fen Wang ◽  
Fang Lin Huang
Keyword(s):  
Cantilever Beam ◽  
Instantaneous Frequency ◽  
Damage Identification ◽  
Energy Operator ◽  
Dimension Function ◽  
Time Varying ◽  
Breathing Crack ◽  
Damage Location ◽  
Damage Degree ◽  
Damage Indices

Damage identification for a cantilever beam with a breathing crack was presented based on instantaneous frequency(IF). One time-varying stiffness model was introduced by considering the breathing effect of the crack in vibration. A simplified single-degree-of-freedom(SDOF) time-varying dynamic differential equation was built. Relationships between the structural instantaneous frequencies (IFs) and damage location and degree were analyzed. IFs of the free vibration displacements were estimated by using phase difference and Teager energy operator (TEO).Moreover the influence of noise on IFs estimation was discussed. Damage indices were built by IFs and the damage degree was identified. Structural IFs are two-dimension function of damage location and degree and the intra-wave phenomenon of IFs verified the non-linearity of damaged structure. The damage indices based on IFs are more reliable than traditional frequency on identifying damage degree and have some anti-noise properties.

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