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.

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.

scholarly journals Vibration control of a lead zirconate titanate structure considering controller–structure interactions

2018 ◽  
Vol 37 (4) ◽  
pp. 1201-1218 ◽  
Author(s):  
Xingjian Dong ◽  
Zhike Peng ◽  
Guang Meng
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
State Space ◽  
State Space Model ◽  
Element Model ◽  
The State ◽  
Laminated Plate ◽  
Space Model ◽  
Model Based ◽  
The Finite Element Model

This study focuses on integrating an active vibration controller into the finite element model of a piezoelectric laminated plate with the controller–structure interactions considered. A finite element model of a piezoelectric laminated plate is formulated using the third-order shear deformation theory. A state-space model is set up by performing a system identification technique. The state-space model is then used to design an optimal vibration controller. Considering that the finite element model is more appropriate than state-space model for dynamic simulation, the state-space model-based controller is integrated into the finite element model to capture the controller–structure interactions. The results obtained by applying vibration controller in state-space model are also presented to make a comparison. It is numerically demonstrated that the controller–structure interactions occur and cause performance degradation in case that the state-space model-based controller works with the finite element model. There is no prior guarantee that a state-space model-based controller satisfying the control requirements still works well in closed loop with the finite element model. The results of this study can be used to evaluate the controller performance for the piezoelectric smart structures during the preliminary design stage.

Stiffness Simulation Analysis of Rubber Bush Mountings Subjected to Tilting Deflection

2013 ◽  
Vol 765-767 ◽  
pp. 341-344
Author(s):  
Bai Qin ◽  
Chao Wu ◽  
Bo Zhang ◽  
Quan Fu Wang ◽  
Ya Juan Ji
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Finite Element Model ◽  
Simulation Model ◽  
Axial Length ◽  
Simulation Analysis ◽  
Element Model ◽  
Simulation Data ◽  
Model Based ◽  
The Finite Element Model

The finite element model of rubber bush mountings is built up. And the value of the reduced tilting stiffness is obtained directly by solving the model. The simulation data and the experimental data can be seen to agree very closely. This fully proves the reliability of the simulation model. Based on this simulation model, which has been parameterized, the influence of the axial length and inner and outer radii on the reduced tilting stiffness of rubber bush is studied by using the co-simulation of MATLAB and ANSYS.

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.

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 Sensitivity Analysis of the Influence of Structural Parameters on Dynamic Behaviour of Highly Redundant Cable-Stayed Bridges

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
B. Asgari ◽  
S. A. Osman ◽  
A. Adnan
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Model Updating ◽  
Structural Parameters ◽  
Element Model ◽  
Structural Behavior ◽  
Model Tuning ◽  
The Finite Element Model ◽  
Cable Stayed Bridges

The model tuning through sensitivity analysis is a prominent procedure to assess the structural behavior and dynamic characteristics of cable-stayed bridges. Most of the previous sensitivity-based model tuning methods are automatic iterative processes; however, the results of recent studies show that the most reasonable results are achievable by applying the manual methods to update the analytical model of cable-stayed bridges. This paper presents a model updating algorithm for highly redundant cable-stayed bridges that can be used as an iterative manual procedure. The updating parameters are selected through the sensitivity analysis which helps to better understand the structural behavior of the bridge. The finite element model of Tatara Bridge is considered for the numerical studies. The results of the simulations indicate the efficiency and applicability of the presented manual tuning method for updating the finite element model of cable-stayed bridges. The new aspects regarding effective material and structural parameters and model tuning procedure presented in this paper will be useful for analyzing and model updating of cable-stayed bridges.

Biodynamics of Human Thorax With Body Armors Subject to Bullet Impact

2001 ◽  
Author(s):  
Y. W. Kwon ◽  
J. A. Lobuono
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Body Armor ◽  
Projectile Impact ◽  
Human Thorax ◽  
Trachea And Bronchi ◽  
Armor System ◽  
The Finite Element Model

Abstract The objective of this study is to develop a finite element model of the human thorax with a protective body armor system so that the model can adequately determine the thorax’s biodynamical response from a projectile impact. The finite element model of the human thorax consists of the thoracic skeleton, heart, lungs, major arteries, major veins, trachea, and bronchi. The finite element model of the human thorax is validated by comparing the model’s results to experimental data obtained from cadavers wearing a protective body armor system undergoing a projectile impact.

Dynamic Analysis of a Turbocharger Centrifugal Compressor Impeller

1991 ◽  
Author(s):  
V. Ramamurti ◽  
D. A. Subramani ◽  
K. Sridhara
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Centrifugal Compressor ◽  
Element Model ◽  
Simplified Model ◽  
Cyclic Symmetry ◽  
Compressor Impeller ◽  
Cyclic Symmetric ◽  
The Finite Element Model

Abstract Stress analysis and determination of eigen pairs of a typical turbocharger compressor impeller have been carried out using the concept of cyclic symmetry. A simplified model treating the blade and the hub as isolated elements has also been attempted. The limitations of the simplified model have been brought out. The results of the finite element model using the cyclic symmetric approach have been discussed.

Analysis of Effective Pre-Stress of Continuous Rigid Frame Bridge in Service Based on Inversion Theory

2013 ◽  
Vol 671-674 ◽  
pp. 1012-1015
Author(s):  
Zhao Ning Zhang ◽  
Ke Xing Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Inversion Method ◽  
Vertical Deflection ◽  
Continuous Rigid Frame Bridge ◽  
Rigid Frame ◽  
Inversion Theory ◽  
Rigid Frame Bridge ◽  
The Finite Element Model

Due to the environment, climate, loads and other factors, the pre-stress applied to the beam is not a constant. It is important for engineers to track the state of the pre-stress in order to ensure security of the bridge in service. To solve the problem mentioned above, the paper puts forward a new way to analyze the effective pre-stress using the displacement inversion method based on the inversion theory according to the measured vertical deflection of the bridge in service at different time. The method is a feasible way to predict the effective pre-stress of the bridge in service. Lastly, taking the pre-stressed concrete continuous rigid frame bridge for example, the effective pre-stress is analyzed by establishing the finite element model.

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