137 Operational Stress Analysis of Engine Main Bearing Casing : Effective Modal Reduction Method for Large Scale Finite Element Model in MBD

The complexities and the economic computational infeasibility associated in some cases, with three-dimensional finite element models, has imposed a motive for many investigators to accept numerical modeling simplification solutions such as assuming two-dimensional (2D) plane strain conditions in simulation of several supported-deep excavation problems, especially for cases with a relatively high aspect ratio in plan dimensions. In this research, a two-dimensional finite element model was established to simulate the behavior of the supporting system of a large-scale deep excavation utilized in the construction of an underground metro station Rod El Farrag project (Egypt). The essential geotechnical engineering properties of soil layers were calculated using results of in-situ and laboratory tests and empirical correlations with SPT-N values. On the other hand, a three-dimensional finite element model was established with the same parameters adopted in the two-dimensional model. Sufficient sensitivity numerical analyses were performed to make the three-dimensional finite element model economically feasible. Results of the two-dimensional model were compared with those obtained from the field measurements and the three-dimensional numerical model. The comparison results showed that 3D high stiffening at the primary walls’ corners and also at the locations of cross walls has a significant effect on both the lateral wall deformations and the neighboring soil vertical settlement.

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Stress Analysis of Laminated Glass under Uniform Lateral Pressure

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.418-420.50 ◽

2011 ◽

Vol 418-420 ◽

pp. 50-54

Author(s):

Shi Hong Pang ◽

Juan Rong Ma ◽

Zhen Zhu Ma ◽

Li Chuang Wang

Keyword(s):

Finite Element ◽

Shear Modulus ◽

Finite Element Model ◽

Stress Analysis ◽

Lateral Pressure ◽

Element Model ◽

Maximum Principal Stress ◽

Laminated Glass ◽

Load Duration ◽

Simulation Results

The shear modulus of PVB and SGP interlayer is analyzed. With the same conditions of load duration and temperature, the shear modulus of SGP interlayer is about fifteen times than that of PVB interlayer. A finite element model of laminated glass is established in this paper. The simulation results show that the maximum principal stress contours of PVB laminated glass change from a circular to a petal-shaped one and those of SGP laminated glass change form a quadrangular to a square-shaped one when the temperature rises from 20 degrees Celsius to 50 degrees Celsius.

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Robust finite element model updating of a large-scale benchmark building structure

STRUCTURAL ENGINEERING AND MECHANICS ◽

10.12989/sem.2012.43.3.371 ◽

2012 ◽

Vol 43 (3) ◽

pp. 371-394 ◽

Cited By ~ 4

Author(s):

E. Matta ◽

A. De Stefano

Keyword(s):

Finite Element ◽

Finite Element Model ◽

Large Scale ◽

Model Updating ◽

Element Model ◽

Finite Element Model Updating ◽

Building Structure

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Simulation Analysis of a Multiple-Vehicle, High-Speed Train Collision Using a Simplified Model

Shock and Vibration ◽

10.1155/2018/9504141 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

Suchao Xie ◽

Weilin Yang ◽

Ping Xu

Keyword(s):

Finite Element ◽

Finite Element Model ◽

High Speed ◽

Large Scale ◽

Computing Time ◽

Element Model ◽

Vehicle Body ◽

Railway Vehicle ◽

Storage Space ◽

High Speed Train

To solve the problems associated with multiple-vehicle simulations of railway vehicles including large scale modelling, long computing time, low analysis efficiency, need for high performance computing, and large storage space, the middle part of the train where no plastic deformation occurs in the vehicle body was simplified using mass and beam elements. Comparative analysis of the collisions between a single railway vehicle (including head and intermediate vehicles before, and after, simplification) and a rigid wall showed that variations in impact kinetic energy, internal energy, and impact force (after simplification) are consistent with those of the unsimplified model. Meanwhile, the finite element model of a whole high-speed train was assembled based on the simplified single-vehicle model. The numbers of nodes and elements in the simplified finite element model of the whole train were 63.4% and 61.6%, respectively, compared to those of the unsimplified model. The simplified whole train model using the above method was more accurate than the multibody model. In comparison to the full-size finite element model, it is more specific, had more rapid computational speed, and saved a large amount of computational power and storage space. Finally, the velocity and acceleration data for every car were discussed through the analysis of the collision between two simplified trains at various speeds.

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Clustering of Parameter Sensitivities: Examples from a Helicopter Airframe Model Updating Exercise

Shock and Vibration ◽

10.1155/2009/982439 ◽

2009 ◽

Vol 16 (1) ◽

pp. 75-87 ◽

Cited By ~ 10

Author(s):

H. Shahverdi ◽

C. Mares ◽

W. Wang ◽

J.E. Mottershead

Keyword(s):

Finite Element ◽

Finite Element Model ◽

Large Scale ◽

Structural Changes ◽

Model Updating ◽

Mass Density ◽

Main Tool ◽

Element Model ◽

Sensitivity Matrix ◽

Comparative Results

The need for high fidelity models in the aerospace industry has become ever more important as increasingly stringent requirements on noise and vibration levels, reliability, maintenance costs etc. come into effect. In this paper, the results of a finite element model updating exercise on a Westland Lynx XZ649 helicopter are presented. For large and complex structures, such as a helicopter airframe, the finite element model represents the main tool for obtaining accurate models which could predict the sensitivities of responses to structural changes and optimisation of the vibration levels. In this study, the eigenvalue sensitivities with respect to Young's modulus and mass density are used in a detailed parameterisation of the structure. A new methodology is developed using an unsupervised learning technique based on similarity clustering of the columns of the sensitivity matrix. An assessment of model updating strategies is given and comparative results for the correction of vibration modes are discussed in detail. The role of the clustering technique in updating large-scale models is emphasised.

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