• Title/Summary/Keyword: FEM(Finite Element Model)

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Implementation of finite element and artificial neural network methods to analyze the contact problem of a functionally graded layer containing crack

  • Yaylaci, Murat;Yaylaci, Ecren Uzun;Ozdemir, Mehmet Emin;Ay, Sevil;Ozturk, Sevval
    • Steel and Composite Structures
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    • 제45권4호
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    • pp.501-511
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    • 2022
  • In this study, a two-dimensional model of the contact problem has been examined using the finite element method (FEM) based software ANSYS and based on the multilayer perceptron (MLP), an artificial neural network (ANN). For this purpose, a functionally graded (FG) half-infinite layer (HIL) with a crack pressed by means of two rigid blocks has been solved using FEM. Mass forces and friction are neglected in the solution. Since the problem is analyzed for the plane state, the thickness along the z-axis direction is taken as a unit. To check the accuracy of the contact problem model the results are compared with a study in the literature. In addition, ANSYS and MLP results are compared using Root Mean Square Error (RMSE) and coefficient of determination (R2), and good agreement is found. Numerical solutions are made by considering different values of external load, the width of blocks, crack depth, and material properties. The stresses on the contact surfaces between the blocks and the FG HIL are examined for these values, and the results are presented. Consequently, it is concluded that the considered non-dimensional quantities have a noteworthy influence on the contact stress distributions, and also, FEM and ANN can be efficient alternative methods to time-consuming analytical solutions if used correctly.

전달 행렬법과 유한요소법을 이용한 중공 크랭크축의 강제 진동 해석 (Forced Vibration Analysis of a Hollow Crankshaft by using Transfer Matrix Method and Finite Element Method)

  • 김관주;최진욱
    • 한국자동차공학회논문집
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    • 제5권6호
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    • pp.44-52
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    • 1997
  • As part of the effort to reduce the weight of powertrain, a hollow crankshaft has been designed. The mass reduction of the crankshaft changes the dynamic properties of the crankshaft such as moment of inertia, and torsional, bending stiffness. The purpose of this paper is to compare the dynamic behavior of the hollow crankshaft with that of the original, solid crankshaft. Global dynamic behavior of the crankshaft is analyzed bgy the transfer matrix method(TMM). The crankshaft has been modeled by 38 lumped mass and stiffness elements. The dynamic patameters of each lumped element are provided by Finite Element Method(FEM). The responses of the crankshaft from TMM are fed back as loading conditions to the Finite Element model to obtain dynamic stresses for critical areas of the crankshaft.

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FEM을 이용한 Cage 삽입 시 안정성에 관한 연구 (A study on the placing cage stability using FEM)

  • 박기훈;박정호;조우석;김현수
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 추계학술대회
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    • pp.1364-1367
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    • 2003
  • These days, spinal interbody arthrodesis using fusion cage is very popular. The cage used for the spinal interbody arthrodesis is mainly inserted from the posterior of the spine. Accordingly, there could possibly occur damages at posterior and results in instability of structure. Moreover, one or two cages are inserted depending on the patients. In this study, it is attempted to evaluate the stability quantitatively by comparing two cases where one and two cages are inserted. For this purpose, a very fine 3-dimensional finite element model of vertebra is generated from the MRI data. From this vertebra model, two models are made: one with one cage and the other with two cages. Finally, finite element analys is performed for these two models and both of the mechanical behaviors are examined In addition, the effect on the stability is evaluated and compared quantitatively.

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성능기반 구조내화설계를 위한 단방향 연성해석 사용자가이드 조사에 관한 연구 (A Study on the Investigation of Users Guide of One-Way Coupled Analysis for Performance-Based Structural Fire Resistance Design)

  • 권영진
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2021년도 가을 학술논문 발표대회
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    • pp.96-97
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    • 2021
  • In the Building Act, performance-based fire safety design is being promoted for institutionalization. The behavior of the structure against fire conditions can be predicted by using the advanced numerical analysis method based on the FEM (Finite Element Method) to predict the entire structural behavior including the behavior of the structure, but there is a limit to expressing the fire properties of the space and predicting the fire properties It is difficult to determine the variables to be transmitted to the FEM (Finite Element Method) model from the fire simulation results using FDS (Fire Dynamics Simulator). Accordingly, the purpose of this study is to introduce the code user's manual for FDS and FEM unidirectional coupling analysis.

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유한요소 LES법에 의한 축류 회전차 팁 틈새의 유동해석 (Flow Analysis in the Tip Clearance of Axial Flow Rotor Using Finite-Element Large-Eddy Simulation Method)

  • 이명호
    • Journal of Advanced Marine Engineering and Technology
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    • 제33권5호
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    • pp.686-695
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    • 2009
  • Flow characteristics in linear axial cascade have been studied using large eddy simulation(LES) based on finite element method(FEM) to investigate details of the leakage flow in the tip clearance of axial flow rotor. STAR-CD(FVM) and PAT-Flow(FEM) have been adopted to solve the Navier-Stokes equations for the simulation of the unsteady turbulent flow. Numerical results from the present study have been compared with the existing experimental results to investigate a tip clearance effect on velocity profile and static pressure distribution on blade surface at various spanwise positions. Both simulation results agree well with the experimental data. However, it has been shown that the results of finite-element large-eddy simulation agree better with experimental data than $k-{\varepsilon}$ turbulent model based on finite volume method regarding the tip vortex geometry and static pressure distribution at the center of the tip vortex core. As a result of this study, it is shown that finite-element large-eddy simulation method can predict more exactly on the tip leakage vortex flow and behind flow field.

Large deformation bending analysis of functionally graded spherical shell using FEM

  • Kar, Vishesh Ranjan;Panda, Subrata Kumar
    • Structural Engineering and Mechanics
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    • 제53권4호
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    • pp.661-679
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    • 2015
  • In this article, nonlinear finite element solutions of bending responses of functionally graded spherical panels are presented. The material properties of functionally graded material are graded in thickness direction according to a power-law distribution of volume fractions. A general nonlinear mathematical shallow shell model has been developed based on higher order shear deformation theory by taking the geometric nonlinearity in Green-Lagrange sense. The model is discretised using finite element steps and the governing equations are obtained through variational principle. The nonlinear responses are evaluated through a direct iterative method. The model is validated by comparing the responses with the available published literatures. The efficacy of present model has also been established by demonstrating a simulation based nonlinear model developed in ANSYS environment. The effects of power-law indices, support conditions and different geometrical parameters on bending behaviour of functionally graded shells are obtained and discussed in detail.

A Shape Optimization of Universal Motor using FEM and Evolution Strategy

  • Shin, Pan-Seok
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • 제2B권4호
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    • pp.156-161
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    • 2002
  • This paper proposes an optimized universal motor for improving its performance using the finite element method (FEM) with the (1+1) Evolution Strategy (ES) algorithm. To do this, various design parameters are modified, such as air gap length, shape of motor slot, pole shoe, pole width, and rotor shaft diameter. Two parameters (arc length of stator pole and thickness of pole shoe) are chosen and optimized using the program, and the optimized model is built and tested with a performance measuring system. The measured values of the model are compared with those of the initial and the optimized model to prove the algorithm. As a result, the final model improves its performance compared with those of the initial model.

Improvement of the Representative Volume Element Method for 3-D Scaffold Simulation

  • Cheng Lv-Sha;Kang Hyun-Wook;Cho Dong-Woo
    • Journal of Mechanical Science and Technology
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    • 제20권10호
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    • pp.1722-1729
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    • 2006
  • Predicting the mechanical properties of the 3-D scaffold using finite element method (FEM) simulation is important to the practical application of tissue engineering. However, the porous structure of the scaffold complicates computer simulations, and calculating scaffold models at the pore level is time-consuming. In some cases, the demands of the procedure are too high for a computer to run the standard code. To address this problem, the representative volume element (RVE) theory was introduced, but studies on RVE modeling applied to the 3-D scaffold model have not been focused. In this paper, we propose an improved FEM-based RVE modeling strategy to better predict the mechanical properties of the scaffold prior to fabrication. To improve the precision of RVE modeling, we evaluated various RVE models of newly designed 3-D scaffolds using FEM simulation. The scaffolds were then constructed using microstereolithography technology, and their mechanical properties were measured for comparison.

운동자계문제의 해석을 위한 유한요소법에 관한 연구 (Travelling Magnetic Field Problem Analyses by Finite Element Method)

  • 한필완;이주
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 A
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    • pp.76-78
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    • 1999
  • This paper presents Galerkin- and Upwind-finite element analyses solution in the travelling magnetic filed problem. The travelling magnetic field problem is subject to convective- diffusion equation. Therefore, the solution derived from Galerkin-FEM with linear interpolation function may oscillate between the adjacent nodes. A simple model with Derichlet, Noumann and periodic boundary condition respectively, have been analyzed to investigate stabilities of solutions. It is concluded that the solution of Galerkin-FEM may oscillate according to boundary condition and element type, but that of Upwind-FEM is stable regardless boundary condition.

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Shear-deformable finite element for free vibrations of laminated composite beams with arbitrary lay-up

  • Kahya, Volkan;Karaca, Sebahat;Vo, Thuc P.
    • Steel and Composite Structures
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    • 제33권4호
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    • pp.473-487
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    • 2019
  • A shear-deformable finite element model (FEM) with five nodes and thirteen degrees of freedom (DOFs) for free vibrations of laminated composite beams with arbitrary lay-up is presented. This model can be capable of considering the elastic couplings among the extensional, bending and torsional deformations, and the Poisson's effect. Lagrange's principle is employed in derivation of the equations of motion, and thus the element matrices are obtained. Comparisons of the present element's results with those in experiment, available literature and the 3D finite element analysis software (ANSYS(R)) are made to show its accuracy. Some further results are given as referencing for the future studies in vibrations of laminated composite beamst.