IDENTIFICATION OF PARAMETER OF TRUSS STRUCTURE BY LIMITED STATIC STRAIN MEASUREMENT (original) (raw)
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Damage Detection of Truss Structures by Reduction of Degrees of Freedom Using the Serep Method
The Baltic Journal of Road and Bridge Engineering, 2020
Damage detection of bridge structures during their operating lifetime is essential. In this paper, two approaches, All Degrees of Freedom and Reduction of the Degrees of Freedom methods, are used to detect the damages in structures. The first method considers All Degrees of Freedom of the structure and the second method, Reduction of the Degrees of Freedom. Since the sensors are installed only on a few degrees of freedom, the responses are available for some of them. The Degrees of Freedom must be reduced and System Equivalent Reduction Expansion Process method is one of the most efficient ways to solve the problem. This research aimed to identify the damage of structures using the Modal Strain Energy method by reducing the structural degree of freedom. Two standard examples are used and the results compared to different damage cases to examine the efficiency of the mentioned method. The results illustrated the proper performance of the Reduction of the Degrees of Freedom method to identify the damage in truss structures. By increasing the number of modes, Reduction of the Degrees of Freedom method detects
Journal of Structural …, 2004
The paper reports on relative performance of inverse eigensensitivity and response function methods for structural damage detection, location and quantification using vibration data. In implementing each of these methods, a validated baseline finite element (FE) model for the structure, in its undamaged state, is assumed to be available. Depending on this, a matrix of sensitivity of structural dynamic characteristics, in frequency or modal domains, to changes in values of structural parameters, is constructed. An inverse procedure, based on pseudoinverse theory of matrices, is subsequently applied to identify structural damages based on observed changes in vibration response of the structure. Issues arising out of mismatch between degrees of freedom of the FE model and number of measured degrees of freedom are dealt with by using alternative model reduction/expansion schemes. Illustrative examples on synthetically and experimentally generated vibration data on cantilever beams and a three-storied building frame are presented.
A Non-Baseline Damage Identification Method Based on the Static Strain Response
A non-base line damage identification method based on the distributed static strain response measurement is presented in this paper. A new approach for damage localization and quantification has been derived and verified with the numerical simulation results. The structural condition at the intact state is not required for the identification or localization of the damage. Sensor configuration to be installed on the structure along with the measured response can be used to identify and localize presence of any damage. To examine and illustrate the damage identification method, a numerical simulation study on a beam type structure was performed.
Bridge health monitoring and damage identification of truss bridge using strain measurements
Advances in Mechanical Engineering
A novel technique to identify bridge damage using genetic algorithms and simulated annealing is proposed in this article. In the proposed method, the cross-sectional area of the damaged member is set as a variable that can be updated. An objective function was investigated to estimate the current condition of the damaged members. This function is the relationship between the measured strain and the analytical strain at the damage location. To obtain better agreement, the parameters were then identified using a genetic algorithm and simulated annealing to minimize the objective function. The proposed method was verified by a truss bridge and can directly estimate the damage based on strain measurements.
This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/authorsrights a b s t r a c t An efficient method is proposed to find multiple damage locations in structural systems. The change of static strain energy (SSE) due to damage is used to establish an indicator for determining the damage location. The SSE is determined using the static analysis information extracted from a finite element modeling. In order to assess the performance of the proposed method for structural damage detection, some benchmark structures having a number of damage scenarios are considered. Numerical results demonstrate that the method can accurately locate the structural damage when considering the measurement noise. The efficiency of the proposed indicator for finding the damage site is also compared with a modal strain energy based index (MSEBI) provided in the literature.
E3S web of conferences, 2022
Developing countries will always engage in infrastructure development in various regions, and one notable aspect of this development is the construction of steel frame bridges. Bridges are complex structures with a myriad of challenges. The increasing number of cases of steel frame bridge collapses has prompted humans to become more conscious of Structural Health Monitoring (SHM) activities. In order to implement this, the development of a straightforward structural damage detection method has been pursued, suitable for both simple and highly complex structures, commonly referred to as Vibration-Based Damage Detection (VBDD). Various algorithms have been proposed to achieve the goal of identifying structural damage, enabling prompt and accurate decision-making in handling such situations. This article delves into the discussion of several proposed algorithms for achieving this objective.
During operation, a variety of factors, including earthquakes, wind, fatigue, the environment, and many others, can always cause damage to structures and the characteristics of the structure change as a result of the damage. The availability of low-cost methods for detecting damage in truss bridges makes it possible to examine a greater number of operating bridges and ultimately reduces future losses and risks. As a result, researchers' pursuit of suitable methods for detecting damage in structures has grown significantly over time. Bridges have always been the focus of researchers' efforts to comprehend their behavior and develop methods for identifying damage because of their significance as the infrastructure of every nation. In this study, an eight-span truss bridge was subjected to a moving load in a laboratory process, and the vertical displacement response of only one desired point of the truss lower chord is measured, in the damaged and intact condition. On the other hand, the influence line diagrams of all truss members have been extracted during the modeling in finite element software. The efficacy of this method in detecting damage in truss bridge screw connections has been evaluated using fourteen distinct damage scenarios. The results show that if damage occurs in the bridge connections, the difference diagram of displacement responses of two healthy and damaged states and the influence line diagram of the member whose connections are damaged will match in terms of shape and can be an indicator to identify the damage. This method works for all of the truss bridge's members, and it has worked even when more than one member was damaged. Considering that this method has been numerically validated in the previous study, using a more accurate displacement sensor with less noise and using conditions closer to those of the numerical analysis improves the accuracy of the results.
Damage localization and quantification by direct structural dynamic parameters updating method
2013
The objective of this paper is detecting the location and extent of structural damage from measured vibration test data based on direct structural finite element model updating. The method is based upon a mathematical model representing the undamaged vibrating structure and a local description of the damage and introduces a new finite element model updating approach for damage detection. The problem of modeling errors and their influence to damage localization accuracy is discussed and an approach to obtain reliable results in this case is presented. The concept of direct updating of individual dynamic parameters is used and according to that algorithms the mathematical function for damage assessment are defined. Then, error matrix of dynamic properties of healthy and damaged structures is established to detect the damage location and severity. For validation of damage detection approaches, two numerical examples are utilized. At the all examples, consider the modal data are incomplete and inverse of rectangular matrices is accomplished by Moore-Penrose inverse matrix without using any multipliers. It will be shown that the proposed procedure is simple to implement and may be useful for structural damage identification.
Truss Structure Health Monitoring Based on Electromechanical Impedance Method
Applied Mechanics and Materials, 2013
Truss structure is widely used in civil engineering applications for its advantages of easy transportation, convenient assembly and uniform loading. However, it is difficult to achieve real-time health monitoring because of connection diversity and complexity of truss structures. As a novel structural health monitoring technique, electro-mechanical impedance method could monitor the health state of one structure by measuring the spectra of impedance or admittance of the piezoelectric elements, which are bonded on the surface of this structure. This approach has the advantages of nonparametric model analysis, easy sensor installation and high local sensitivity, especially in sensitive frequency range. The damage information, which is tested and recorded by using electromechanical impedance method, could convert into intuitive results through neural network because of its good ability for nonlinear mapping. In this paper, a three-layer assembly truss structure was chosen as experiment...
A swift technique for damage detection of determinate truss structures (2)
Engineering with Computers
This paper introduces a novel and robust probable statistical approach for the applied damage detection of determinate truss structures. This technique involves two steps; the first is called most probable damaged element identification step and the second is called probable damage severity prediction step. In the first step, a new index based on modal residual forces plays a major role to independently identify damage-suspected elements for each considered mode. Then among them, the elements, the most probable to damage, are extracted. In the second step, the probable damage severity for each most probable damaged element is individually predicted using a novel statistical approach. Finally, to justify the validity and robustness of the technique, three commonly used bridge trusses including a 29-bar Pratt truss, a 29-bar Warren truss, and finally, a 37-bar K truss under different damage scenarios are thoroughly studied while their modal parameters are corrupted by noise. The obtained results indicate that the method is innovatively capable of swiftly predicting, for determinate truss structures, not only damaged elements but also their damage severities by carrying out solely few structural analyses.