• Title/Summary/Keyword: finite-element modeling

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Analytical Modeling for Reinforced Concrete Beam Deflections Using Layered Finite Elements (층상 유한요소를 이용한 철근콘크리트 보의 처짐 해석모델)

  • 최봉섭;권영웅
    • Journal of the Korea Concrete Institute
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    • v.11 no.5
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    • pp.131-137
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    • 1999
  • The use of higher strength materials with the strength methed of design has resulted in more slender member and shallower sections. For this reason, it is necessary to satisfy the requirements of serviceability even though the structural safety is the most important limit state. This paper is only concerned with the control of deflections in the serviceability. In this study, an analytical model is presented to predict the deflections of reinforced concrete beams to given loading and environmental conditions. This model is based on the finite element approach in which a finite element is generally divided into a number of stiffening effect due to cracking, creep and shrinkage. Comparisons are made with available measured deflections reported by others to assess the capability of the layered beam model. The calculated values of instantaneous and long-term deflection show good agreement with experimental results in the range of tension stiffening parameter $\beta$ between 2.5 and 3.0.

Three dimensional finite elements modeling of FGM plate bending using UMAT

  • Messaoudi, Khalid;Boukhalfa, Abdelkrim;Beldjelili, Youcef
    • Structural Engineering and Mechanics
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    • v.66 no.4
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    • pp.487-494
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    • 2018
  • The purpose of the present paper is to study the bending and free vibration of Functionally Graded Material (FGM) plate using user-defined material subroutine on the finite element software ABAQUS. The FGM plate is simply supported and subjected to sinusoidal and uniform load. The Poisson's ratio is kept constant. The results obtained compared to those available in the literature show the convergence, the exactitude and the efficiency of the method used with various power index of the materials.

Structural Design of a Coil Cover for High Capacity Alternator (대용량 알터네이터의 코일덮개 설계)

  • Kim, Dae-Won;Kim, Jong-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.3
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    • pp.46-51
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    • 2002
  • Recently, High capacity alternator are used fur some special equipments in industry. But, several serious problem are occured, especially, broken coil of rotor, caused by crash with stator on rotating the rotor. Although added coil cover thor protect coil of rotor, coil cover is broken. In this study purpose 2 step for corrected that problems. First, three dimensional finite element method far investigate what is most important point. For that purpose, performed stress analysis of coil and coil cover that modeling and finite analysis by ANSYS software. Second, Apply prestress when winding the coil on stator to modify direction of net force. Vector analysis is used for determine corrected prestress. Result of the analysis and prestress are reviewed.

2-Dimensional Numerical Studies on Thin HTS Film under Time Varying Magnetic Field Using Finite Element Method (변화하는 자기장 하에 있는 고온초전도체에 대한 유한요소법을 이용한 2차원 수치해석 연구)

  • Kwak, K.S.;Lee, H.Y.;Rhee, J.K.;Youm, D.;Yoo, J.;Han, Y.H.;Park, B.J.
    • Progress in Superconductivity
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    • v.13 no.3
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    • pp.151-157
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    • 2012
  • In this paper, we used E-J constitutive law and H-formulation to calculate magnetic field profile, current density, and magnetization of high temperature superconductor (HTS) placed in time varying applied magnetic field. Finite element method (FEM)-based software, Comsol Multiphysics 3.5a, was employed to simulate 2-dimensional model of a superconducting thin strip. The numerical results based on Kim's critical state model were compared with the case of strip in a perpendicular field in the Brandt's paper as well as experimental data observed by Scanning Hall Probe and SQUID.

Seismic Analysis of Statically Determinate Beams Using Moving Support Finite Elements (동지점 유한요소를 이용한 정정보의 지진해석)

  • Kim, Yong-Woo;Lee, Seoung Yeal;Jhung, Myung Jo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2013.04a
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    • pp.194-199
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    • 2013
  • Using moving support finite elements, seismic analysis of statically-determinate beams subjected to support motions is performed to show its accuracy and its ease of use. Examples of cantilever and simply-supported beam subjected to support motions are illustrated and the numerical results are compared with the analytical solutions. The examples show the elements facilitate modeling beams with the conventional 2-noded, Hermitian, Euler-Bernoulli beam element. The comparisons of the results with analytical solutions show good agreements with high accuracy.

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Development of A Web-based Simulation System for Axi-Symmetric Deep Drawing (축대칭 디프드로잉 공정의 웹 기반 해석시스템 개발)

  • 정완진
    • Transactions of Materials Processing
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    • v.12 no.6
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    • pp.550-557
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    • 2003
  • In this study, a web-based system was developed by utilizing finite element method and virtual system designed using Virtual Reality Modeling Language (VRML). The simulation program for axi-symetric sheet forming is developed using finite flement method. The developed system consists of two modules, client module and server module. The client module was developed by using Active-X control. The input data for FEM calculation is transferred to the server module by using communication protocol. Then sever module performs several successive processes: input data generation, forming simulation, conversion of results to VRML format. After that, the results from the simulation can be visualized on the web browser in client computer. Besides, client module offers the capability to control and navigate on virtual forming machine and calculated result. By using this system simulation result can be investigated more realistically in virtual environment including forming machine.

Variational Calculations for Higher Order Mode Cut-off Frequencies of Symmetrical Striplines by the Conformal Mapping (등각사상에 의한 대칭 스트립 전송선의 고차모드 차단주파수의 변분적 계산)

  • 양현규;이상설
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.2
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    • pp.170-175
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    • 2002
  • The cut-off frequencies of higher order modes in a symmetrical stripline are calculated using the variational finite element method combined with the conformal mapping. The conformal mapping is used to Improve the modeling of the infinite transverse extents of a stripline. And then the finite element method is employed to solve the variational equation in the transformed finite region. Comparisons with numerical results found in the literature validate the presented method.

An analytical approach for offshore structures considering soil-structure interaction

  • Ali Sari;Kasim Korkmaz
    • Advances in Computational Design
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    • v.9 no.1
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    • pp.25-38
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    • 2024
  • This paper presents an advanced analytical approach for the design and analysis of fixed offshore structures with soil structure interaction considered. The proposed methodology involves conducting case studies to illustrate and assess the structural response of a structure considering seven different earthquakes, with the primary goal of ensuring there is no global collapse in the structures. The case studies focus on developing a model for structural analysis and its topside, incorporating nonlinear axial and lateral springs to capture soil-pile interaction. Additionally, mass and damping ratios are considered through the use of dashpots in the analyses. Finite Element Software was employed for structural analyses with detailed modeling, with soil spring nodes applied in the entire structure across various depths. After the finite element analysis was carried out, a sensitivity analysis was conducted to quantify and report the effects of different parameters.

Analysis of composite frame structures with mixed elements - state of the art

  • Ayoub, Ashraf
    • Structural Engineering and Mechanics
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    • v.41 no.2
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    • pp.157-181
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    • 2012
  • The paper presents a review of the application of the newly proposed mixed finite element model for seismic simulation of different types of composite frame structures. To evaluate the performance of the element, a comparison with displacement-based and force-based models is conducted. The study revealed that the mixed model is superior to the others in terms of both speed of convergence and numerical stability, and is therefore considered the most practical approach for modeling of composite structures. In this model, the element is derived using independent force and displacement shape functions. The nonlinear response of the frame element is based on the section discretization into fibers with uniaxial material models. The interfacial behavior is modeled using an inelastic interface element. Numerical examples to clarify the advantages of the model are presented for the following structural applications: anchored reinforcing bar problems, composite steel-concrete girders with deformable shear connectors, beam on elastic foundation elements, R/C girders strengthened with FRP sheets, R/C beam-columns with bond-slip, and prestressed concrete girders. These studies confirmed that the model represents a major advancement over existing elements in simulating the inelastic behavior of composite structures.

Evaluation of the seismic performance of off-centre bracing system with ductile element in steel frames

  • Bazzaz, Mohammad;Kheyroddin, Ali;Kafi, Mohammad Ali;Andalib, Zahra
    • Steel and Composite Structures
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    • v.12 no.5
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    • pp.445-464
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    • 2012
  • In order to evaluate the dynamic behavior of passive energy dissipation system, two steps need to be considered for prediction of structural response in the presence of ductile element in an off-centre bracing system. The first is a detailed analysis of the proposed ductile element and the second is the effect of this ductile element on an off-centre bracing system. The use of ductile bracing system is expanding in steel structures in order to increase the force reduction factor. Therefore, regarding the nonlinear behavior of steel material used in an off-centre bracing systems and using ductile element in OBS bracing systems, the seismic evaluation of the mentioned systems seems to be necessary. This paper aims to study linear and nonlinear behavior of steel frames with off-centre bracing system and ductile element, in order to get the best position of these bracing elements. To achieve this purpose, the modeling has been done with ANSYS software. The optimum eccentricity has been obtained by modeling three steel frames with different eccentricities and evaluating the results of them. The analytical results showed that the model OBS-C with 0.3 eccentricities has higher performance among the models.