scholarly journals Statistical damage identification method based on dynamic response sensitivity

2018 ◽  
Vol 39 (3) ◽  
pp. 560-571 ◽  
Author(s):  
Ling Mao ◽  
Shun Weng ◽  
Shu-Jin Li ◽  
Hong-Ping Zhu ◽  
Yan-Hua Sun
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Finite Element Model ◽  
Damage Identification ◽  
Element Model ◽  
Measured Data ◽  
Response Sensitivity ◽  
Identification Method ◽  
The Finite Element Model ◽  
Statistical Damage

The traditional deterministic damage detection method is based on the assumption that the measured data and the finite element model are accurate. However, in real situation, there are many uncertainties in the damage identification procedure such as the errors of the finite element model and the measurement noise. Since the uncertainties inevitably exist in the finite element models and measured data, the statistic method which considers the uncertainty has wide practical application. This paper proposes a statistical damage identification method based on dynamic response sensitivity in state-space domain. Considering the noise of the finite element model and measured acceleration response, the statistical variations of the damaged finite element model are derived with perturbation method which is based on a Taylor series expansion of the response vector and verified by Monte Carlo technique. Afterward, the probability of damage existence for each structural element is estimated using the statistical characteristic of the identified structural parameters. A numerical simply supported beam under the moving load is applied to demonstrate the accuracy and efficiency of the proposed statistical method.

scholarly journals Damage Identification of High-speed Maglev Guideway Girder Based on Modal Identification

2021 ◽  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Health Monitoring ◽  
High Speed ◽  
Damage Identification ◽  
Element Model ◽  
High Tech ◽  
Maglev Train ◽  
Identification Method ◽  
The Finite Element Model

Abstract. As a modern high-tech rail vehicle, the maglev train realizes the non-contact suspension and guidance between the train and the guideway, which greatly reduces the resistance of the system. Due to the high-speed operation characteristics of maglev trains, the structural health monitoring of guideway girders is particularly important for the safety and stability of maglev train operation. This paper takes the maglev train guideway girder as the monitoring target, and the finite element model of the maglev vehicle-guideway is established to simulate the running state of the train passing through the guideway girder. The dynamic response data of the guideway girder is obtained in the finite element model, considering healthy states and different damage states of the guideway girder. Then, a modal-based damage identification method is proposed, which obtains the guideway girder damage sensitive characteristics by decomposing the guideway girder acceleration response signal. Finally, based on the measured guideway girder acceleration data, this paper verifies the effectiveness of the damage identification method in guideway girder structure health monitoring, which provides reference and guidance for the future maintenance of the maglev guideway girder.

An efficient technique for extraction of nonlinear dynamic features in a model-based feature extraction scheme for machine learning–based structural health monitoring

2020 ◽  
pp. 107754632093374
Author(s):  
Mehdi Fathalizadeh Najib ◽  
Ali Salehzadeh Nobari
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Damage Identification ◽  
Element Model ◽  
Model Based ◽  
Damage Indicators ◽  
Input Model ◽  
Harmonic Components ◽  
Nonlinear Autoregressive ◽  
The Finite Element Model

Super-harmonic components in response to the harmonic excitation are sensitive indicators of damages such as breathing cracks in beams or kissing bonds in adhesive joints. In a model-based damage identification process using pattern recognition, these damage indicators can be extracted from the finite element model for all probable damage cases using stepped-sine simulation that necessitates nonlinear transient dynamic analysis with high computational costs. In this study, a procedure based on nonlinear autoregressive with exogenous input model is introduced as an alternative shortcut method for extraction of the damage indicators. As a case study, the finite element model of a beam connected to a rigid support via a flexible adhesive layer was used to investigate the efficiency of the proposed method. Kissing bond was introduced to the model as the source of nonlinearity via contact elements. The results prove that the super-harmonic components of orders up to 3, extracted from the nonlinear autoregressive with exogenous input model, agreed well with those extracted directly from the finite element model, whereas the computational time is reduced by a factor of 1/5. Consequently, the proposed method is very advantageous in the stage of damage pattern database creation in a real-world model-based damage identification process based on pattern recognition.

Instantaneous Dynamic Analysis of the New Stirring Kneader Shaft

2011 ◽  
Vol 221 ◽  
pp. 472-477
Author(s):  
Zhi Min Fan ◽  
Guang Ting Zhou ◽  
Jian Ping Liu
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Dynamic Response ◽  
Finite Element Model ◽  
Dynamic Analysis ◽  
Structural Parameters ◽  
Element Model ◽  
Fatigue Analysis ◽  
Exciting Force ◽  
The Finite Element Model

The finite element model of the stirring kneader shaft was built by PRO/E software, which was inserted into ANSYS. Next, the instantaneous dynamic analysis of the new stirring kneader shaft was carried out. The instantaneous dynamic response of stirring shaft about the exciting force of fluid was obtained, which was to optimize the structural parameters of the stirring shaft. The foundation for the next fatigue analysis was laid based on the instantaneous dynamic response; the fatigue life of stirring kneader shaft can be predicted.

Accurate FEM of Steel-Concrete Composite Box Girder Bridge for Damage Identification Based on Dynamical Experimental Study

2013 ◽  
Vol 330 ◽  
pp. 872-877
Author(s):  
Yi Qiang Xiang ◽  
Li Si Liu ◽  
Shao Jun Li
Keyword(s):  
Experimental Study ◽  
Finite Element ◽  
Finite Element Model ◽  
Damage Identification ◽  
Element Model ◽  
Scale Model ◽  
Box Girder ◽  
Box Girder Bridge ◽  
Girder Bridge ◽  
The Finite Element Model

Based on the results of experiment, this paper discusses about the updating and validation of accurate finite element model for damage identification of the steel-concrete composite box girder bridge. Taking a 5 meters long steel-concrete composite box girder bridge as the research object and the finite element model is established. By means of scale model test the updating of the accurate finite element model has been completed and validation is confirmed.

Dynamic Response Analysis of Ship Hull Structures

2000 ◽  
Vol 37 (03) ◽  
pp. 117-128
Author(s):  
T. V. S. R. Appa Rao ◽  
Nagesh R. Iyer ◽  
J. Rajasankar ◽  
G. S. Palani
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Dynamic Response ◽  
Finite Element Model ◽  
Element Model ◽  
Ship Hull ◽  
Response Analysis ◽  
Dynamic Response Analysis ◽  
Hull Structure ◽  
The Finite Element Model

Finite-element modeling and use of appropriate analytical techniques play a significant role in producing a reliable and economic design for ship hull structures subjected to dynamic loading. The paper presents investigations carried out for the dynamic response analysis of ship hull structures using the finite-element method. A simple and efficient interactive graphical preprocessing technique based on the "keynode" concept and assembly-line procedure is used to develop the finite-element model of the hull structure. The technique makes use of the body plan of a ship hull to build the finite-element model through an interactive session. Stiffened plate/shell finite elements suitable to model the hull structure are formulated and used to model the structure. The finite elements take into account arbitrary placement of stiffeners in an element without increasing the number of degrees-of-freedom of the element. A three-dimensional finite-element model and a procedure based on the Bubnov-Galerkin residual approach are employed to evaluate the effects of interaction between the ship hull and water. Mode superposition technique is used to conduct the dynamic response analysis. The efficiency of the finite elements and the procedures is demonstrated through dynamic analysis of a submerged cantilever plate and a barge when both are subjected to sinusoidal forces. The dynamic responses exhibit expected behavior of the structure and a comparison with the results available in the literature indicate superior performance of the finite element and methodologies developed. Thus, the finite-element models and the procedures are found to be efficient and hence suitable for the dynamic analysis of similar structures.

The Numerical Simulation Research of the Dynamic Response of RC Frame Structure under the Internal Explosion

2014 ◽  
Vol 1065-1069 ◽  
pp. 2090-2094
Author(s):  
Bin Jia ◽  
Xiao Wei Zhu ◽  
Zhu Wen ◽  
Qi Jiang
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Dynamic Response ◽  
Finite Element Model ◽  
Element Model ◽  
Frame Structure ◽  
Rc Frame ◽  
Simulation Research ◽  
Rc Frame Structure ◽  
The Finite Element Model

The finite element model was established in this paper to study the process of dynamic response of RC frame structure under internal explosive loading. The burst point in the model was located in the center of the frame structure .The article analyzed the process of the dynamic response of the frame structure in the explosive environment and the result of the numerical simulation accorded well with the test. The result showed that the finite element model was feasible as well as providesed reference to the design and protection for the building structure.

scholarly journals Structural Damage Identification Based on Transmissibility in Time Domain

Sensors ◽  
2022 ◽  
Vol 22 (1) ◽  
pp. 393
Author(s):  
Yunfeng Zou ◽  
Xuandong Lu ◽  
Jinsong Yang ◽  
Tiantian Wang ◽  
Xuhui He
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Time Domain ◽  
Structural Damage ◽  
Damage Identification ◽  
Element Model ◽  
Time Frequency ◽  
Identification Method ◽  
Structural Damage Identification ◽  
The Time Domain

Structural damage identification technology is of great significance to improve the reliability and safety of civil structures and has attracted much attention in the study of structural health monitoring. In this paper, a novel structural damage identification method based on transmissibility in the time domain is proposed. The method takes the discrepancy of transmissibility of structure response in the time domain before and after damage as the basis of finite element model updating. The damage is located and quantified through iteration by minimizing the difference between the measurements at gauge locations and the reconstruction response extrapolated by the finite element model. Taking advantage of the response reconstruction method based on empirical mode decomposition, damage information can be obtained in the absence of prior knowledge on excitation. Moreover, this method directly collects time-domain data for identification without modal identification and frequent time–frequency conversion, which can greatly improve efficiency on the premise of ensuring accuracy. A numerical example is used to demonstrate the overall damage identification method, and the study of measurement noise shows that the method has strong robustness. Finally, the present work investigates the method through a simply supported overhanging beam. The experiments collect the vibration strain signals of the beam via resistance strain gauges. The comparison between identification results and theoretical values shows the effectiveness and accuracy of the method.

Modeling the Response of Surface Micromachined Thermal Actuators

2005 ◽  
Author(s):  
Amarendra P. Atre
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Reasonable Agreement ◽  
Three Dimensional ◽  
Element Model ◽  
Measured Data ◽  
Linear Finite Element ◽  
Thermal Actuators ◽  
Simulation Results ◽  
The Finite Element Model

Thermal microactuators, devices that use the principle of thermal expansion to amplify motion, have several advantages in comparison with other actuators used to motivate surface micromachined components such as rotary microengines. They provide higher output forces and have simple geometries. Accurate steady-state and transient modeling of such thermal actuators provides a tool for design optimization to obtain better actuator performance. This paper describes the development, modeling issues and results of a three dimensional multiphysics non-linear finite element model of a surface micromachined thermal actuator. The simulation results are compared with experimentally measured data. Reasonable agreement is observed for static actuator deflection response. The measured transient response is observed to be significantly slower than that predicted by the finite element model.

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