The improvement of bolted joints model via finite element model updating method

Efficient schemes to represent mathematical model of thin-sheet metal structures jointed by bolted joints for accurately predict the structure dynamic behaviour has been a significant unresolved issue in structural dynamics community. The biggest challenge is to efficiently incorporate the joints local deformation effects on the developed mathematical model via finite element (FE) method. Generally, the joints local deformation typically exerts on the joints mating area. To solve this issue, this paper proposes efficient schemes to represent mathematical model of thin-sheet metal structures jointed by bolted joints with application to accurately calculate the structure dynamic behaviour using FE model updating method. The initial FE model of the assembled structure was developed by employed Fastener Connector (CFAST) in MSC NASTRAN software to represent the bolted joints while, the inclusion of the local deformation effects at the bolted joints mating area was represented by contact elements. Then, the responses obtained from the FE model was evaluated by weight up with experimental data. FE model updating (FEMU) method then was utilised for minimising prediction discrepancies originated from the initial FE model based on the experimental data. The proposed scheme shows the accuracy of the initial prediction was improved from 25.03 % to 14.65 % while the accuracy of the predicted mode shapes via modal assurance criterion (MAC) analysis were above 0.8. Therefore, the findings offer useful schemes for improving the quality of predicted dynamic behaviour, particularly in the thin-sheet metal jointed structure and the developed model can be used with confident for any subsequence dynamic analyses.

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Representation of bolted joints in a structure using finite element modelling and model updating

JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES ◽

10.15282/jmes.14.3.2020.15.0560 ◽

2020 ◽

Vol 14 (3) ◽

pp. 7141-7151 ◽

Cited By ~ 1

Author(s):

R. Omar ◽

M. N. Abdul Rani ◽

M. A. Yunus

Keyword(s):

Finite Element ◽

Dynamic Behaviour ◽

Model Updating ◽

Complex Structure ◽

Bolted Joints ◽

Model Parameters ◽

Fe Model ◽

Bolted Joint ◽

Fe Modelling ◽

Joint Structure

Efficient and accurate finite element (FE) modelling of bolted joints is essential for increasing confidence in the investigation of structural vibrations. However, modelling of bolted joints for the investigation is often found to be very challenging. This paper proposes an appropriate FE representation of bolted joints for the prediction of the dynamic behaviour of a bolted joint structure. Two different FE models of the bolted joint structure with two different FE element connectors, which are CBEAM and CBUSH, representing the bolted joints are developed. Modal updating is used to correlate the two FE models with the experimental model. The dynamic behaviour of the two FE models is compared with experimental modal analysis to evaluate and determine the most appropriate FE model of the bolted joint structure. The comparison reveals that the CBUSH element connectors based FE model has a greater capability in representing the bolted joints with 86 percent accuracy and greater efficiency in updating the model parameters. The proposed modelling technique will be useful in the modelling of a complex structure with a large number of bolted joints.

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Parametric modeling and updating for bolted joints of aeroengine casings

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406215607900 ◽

2016 ◽

Vol 230 (16) ◽

pp. 2940-2951 ◽

Cited By ~ 8

Author(s):

Xue Zhai ◽

Cheng-Wei Fei ◽

Jian-Jun Wang ◽

Xing-Yu Yao

Keyword(s):

Thin Layer ◽

Model Updating ◽

Parametric Modeling ◽

Bolted Joints ◽

Maximum Relative Error ◽

Fe Model ◽

Fe Modeling ◽

Bolted Joint ◽

Static Stiffness ◽

Fe Model Updating

To establish accurate finite element (FE) model of bolted joint structures of aeroengine stator system (casings), this work implements the parametric FE modeling and updating of bolted joints of aeroengine stator system with multi-characteristic responses (multi-object). Firstly, the parametric FE modeling approach of bolted joint structure was developed based on the thin layer element method. And then the FE model updating thought of aeroengine stator system was developed based on the probabilistic analysis method. Finally, the parametric modeling and updating of the bolted joints of aeroengine stator system with multi-characteristic responses was completed by the optimization iteration calculation of objective function based on the proposed methods and the static stiffness testing data. Through the parametric modeling of bolted joint structures based on the thin layer method, the complexity of FE model of aeroengine casings with many bolted joint structures is reduced. As shown in the FE model updating of casings with multi-characteristic responses analysis, the static stiffness from the updated model are very close to the test data, in which the maximum relative error decreases to 3.9% from 30.52% and the others are less than 3%, so that the design precision of aeroengine stator system with the many and wide variety of bolted joints gets a great improvement. Moreover, the proposed methods of parametric modeling and model updating for multi-characteristic responses are validated to be effective in the simulation and equivalent of the mechanical characteristics of bolted joints in complex systems like aeroengine stator system.

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Comparison of Hybrid Metal-Composite Small-Pin Joints with Conventional Ones in Terms of Static and Fatigue Strength

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.821.479 ◽

2016 ◽

Vol 821 ◽

pp. 479-485

Author(s):

Ganna Beketova ◽

Marina Shevtsova ◽

Volodymyr Symonov

Keyword(s):

Fatigue Strength ◽

Sheet Metal ◽

Thin Sheet ◽

Fatigue Tests ◽

Bolted Joints ◽

Metal Composite ◽

Composite Part ◽

Out Of Plane ◽

Thin Sheet Metal ◽

Plane Direction

The current research deals with special hybrid metal-composite joints (MCJ) which use thin sheet-metal reinforcement with small die-fixed pins (2-3 mm) embedded into the composite part of the joint. This technological trick significantly and positively influences strength of the metal-composite bolted joints loaded in out-of-plane direction. This fact was proved by comparison of pull-off static and fatigue tests results of MCJs with and without reinforcement.

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Comparability of structured and flat reference specimens made of thin sheet metal

Materials Testing ◽

10.3139/120.110748 ◽

2015 ◽

Vol 57 (6) ◽

pp. 567-573 ◽

Cited By ~ 1

Author(s):

Fedor Kazak ◽

Sabine Weiß

Keyword(s):

Sheet Metal ◽

Thin Sheet ◽

Thin Sheet Metal ◽

Reference Specimens

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Experimental and Numerical Analysis of Blanking for Thin Sheet Metal Parts

International Journal of Forming Processes ◽

10.3166/ijfp.4.319-333 ◽

2001 ◽

Vol 4 (3-4) ◽

pp. 319-333

Author(s):

Vincent Lemiale ◽

Philippe Picart ◽

Sébastien Meunier

Keyword(s):

Numerical Analysis ◽

Sheet Metal ◽

Thin Sheet ◽

Metal Parts ◽

Sheet Metal Parts ◽

Thin Sheet Metal

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Vision-Based Structural FE Model Updating Using Genetic Algorithm

Applied Sciences ◽

10.3390/app11041622 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1622

Author(s):

Gun Park ◽

Ki-Nam Hong ◽

Hyungchul Yoon

Keyword(s):

Genetic Algorithm ◽

Model Updating ◽

Structural Parameters ◽

Fe Model ◽

Structural Members ◽

Stiffness Reduction ◽

Before And After ◽

Scale Test ◽

Fe Model Updating ◽

Story Building

Structural members can be damaged from earthquakes or deterioration. The finite element (FE) model of a structure should be updated to reflect the damage conditions. If the stiffness reduction is ignored, the analysis results will be unreliable. Conventional FE model updating techniques measure the structure response with accelerometers to update the FE model. However, accelerometers can measure the response only where the sensor is installed. This paper introduces a new computer-vision based method for structural FE model updating using genetic algorithm. The system measures the displacement of the structure using seven different object tracking algorithms, and optimizes the structural parameters using genetic algorithm. To validate the performance, a lab-scale test with a three-story building was conducted. The displacement of each story of the building was measured before and after reducing the stiffness of one column. Genetic algorithm automatically optimized the non-damaged state of the FE model to the damaged state. The proposed method successfully updated the FE model to the damaged state. The proposed method is expected to reduce the time and cost of FE model updating.

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