• Title/Summary/Keyword: Finite element analysis

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Contact Heat Transfer Coefficient for Finite Element Analysis in Warm Forging Processes (온간단조 공정의 계면열전달계수)

  • Kang J.H.;Ko B.H.;Jae J.S.;Kang S.S.
    • Transactions of Materials Processing
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    • v.15 no.3
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    • pp.183-188
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    • 2006
  • Heat transfer coefficients have great influence on finite element analysis results in elevated temperature forging processes. Experimentally calculated contact heat transfer coefficient is not suitable for one-time finite element analysis because analyzed temperature will be appeared to be too low. To get contact heat transfer coefficient for one-time finite element analysis, tool temperature in operation was measured with thermocouple and repeated finite element analysis was performed with experimentally calculated contact and cooling heat transfer coefficient. Surface temperature of active tool was obtained comparing measurement and analysis results. Contact heat transfer coefficient for one-time finite element analysis was achieved analyzing surface temperature between repeated finite element analysis and one-time finite element analysis results.

A Study on the Finite Element Analysis of Axisymmetric Hydrostatic Bulge forming Processes (축대칭 액압벌지 성형공정의 유한요소해석에 관한 연구)

  • Yun S. H.;Jin I. T.;Gu Y.;Ryoo I. I.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.115-119
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    • 2001
  • This paper presents development of a Finite Element Analysis program. The program was developed on the based of second-dimensional plane strain rigid plasticity finite element analysis and an implicit program is coded. The program was tested by being applied to the axisymetric hydrostatic bulge forming processes using the circle dies. By the Finite Element Analysis at the fluid in chamber and at the blank material, we could know that the hydrostatic bulge forming processes can be influenced of material, the diameter of product and the forming velocity The developed Finite Element Analysis program was approved by the analysis results about forming variables.

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Evaluation of Efficiency Uncertainty for Three-phase Induction Motor using Finite Element Analysis (유한요소 해석을 이용한 3상 유도전동기의 효율 불확도 평가)

  • Lee, Ho-Hyun;Park, Han-Seok;Jun, Hee-Deuk;Woo, Kyung-Il
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.66 no.4
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    • pp.163-168
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    • 2017
  • This paper presented an evaluation method for the efficiency uncertainty of a three-phase induction motor using finite element analysis. The motor efficiency in the finite element analysis is calculated by the loss separation method as in the actual test. In the process of evaluating the efficiency uncertainty, the difference between the finite element analysis and the actual test is the method of calculating the type-A / B standard uncertainty of the input quantity to estimate the efficiency and each losses. For the input quantities which can confirm the instantaneous values with respect to time, the type-A standard uncertainty in the finite element analysis is calculated from the RMS values or average values having separate periods in the steady state. And, the type-B standard uncertainty in the finite element analysis is assumed to be zero. Also, this paper compared and analyzed the efficiency uncertainty evaluated by the proposed method and the efficiency uncertainty through the actual test.

Finite Element Analysis of the Stress Concentrations for Butt Welded Joints (유한요소 해석에 의한 맞대기 용접 이음의 응력집중에 과한 연구)

  • 구병춘;최병일;김재훈
    • Journal of Welding and Joining
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    • v.22 no.4
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    • pp.59-64
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    • 2004
  • The purpose of this study is to investigate the influence of weld bead profiles on stress concentration factors of double V groove butt-welded joints. The influence of three parameters such as toe radii, flank angles and bead heights on the stress concentration factors is studied by finite element analysis. It is shown that the three parameters have similar effects on the stress concentration factors. Finally a formula to estimate the stress concentration factors considering the three parameters and others is proposed and estimated results are compared with the results obtained by finite element analysis.

Boundary stress resolution and its application to adaptive finite element analysis

  • Deng, Jianhui;Zheng, Hong;Ge, Xiurun
    • Structural Engineering and Mechanics
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    • v.6 no.1
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    • pp.115-124
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    • 1998
  • A novel boundary stress resolution method is suggested in this paper, which is based upon the displacements of finite element analysis and of high precision with stress boundary condition strictly satisfied. The method is used to modify the Zienkiewicz-Zhu ($Z^2$) a posteriori error estimator and for the h-version adaptive finite element analysis of crack problems. Successful results are obtained.

Nonlinear finite element analysis on the pullout behavior of the mechanical anchorage of reinforcement in concrete (기계적 정착된 철근의 인발거동에 대한 비선형 유한요소 해석)

  • 천성철;이성호;오보환;박형철;나환선;김상구
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.132-135
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    • 2003
  • Mechanical anchorage can substitute a standard hook. To enhance the workability and economical benefit of mechanical anchorage, the size of anchor plate should be optimized. In this paper, the pull-out behaviors such as strength, failure mode, and crack patterns of mechanically anchored reinforcement in concrete are investigated using nonlinear finite element analysis. The nonlinear finite element analysis results are consistent with the experimental results. These results show that the optimal anchor plates can be designed using the nonlinear finite element analysis.

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Behavior of Soil-Reinforced Segmental Retaining Walls Subjected to Earthquake Loading (보강토 옹벽의 지진시 거동)

  • 유충식
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.379-386
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    • 2000
  • This paper presents the results of finite element analysis on the seismic response of a soil-reinforced segmental retaining wall subjected to a prescribed earthquake record. The results of finite element analysis indicate that the maximum wall displacement occurs at the top, exhibiting a cantilever type of wall movement. Also revealed is that the increase in reinforcement force is more pronounced in the upper part of the reinforced zone, resulting in a more or less uniform distribution. None of the design guidelines appears to be able to correctly predict the dynamic force increase when compared with the results of finite element analysis. The calculation model adopted by the NCMA guideline, however, appears to compare better with the results of finite element analysis as well as field survey than the FHWA guideline. Based on the findings from this study, a number of implications to the current design methods are discussed.

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Improvement of the Stamping Process for Sheet Metal Prototypes of an Auto-body with Finite Element Analysis (유한요소해석을 이용한 차체시작부품 프레스성형 공정 개선)

  • Kim, Se-Ho
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.4
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    • pp.496-504
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    • 2011
  • This paper introduces a CAE-based design procedure in the press forming process for the fabrication of sheet metal parts used in proto-cars. The finite element analysis reveals formability problems during the forming process of a floor member and a front cross member that constitute a rear floor assembly. The study proposes the modification of the initial blank shape or intermediate trimming of the product to prevent failure during forming. It is confirmed by the tryout process as well as the finite element analysis that sound prototype can be obtained with the modified design. The finite element analysis result also provides fairly good prediction of springback amounts used for the post-compensation of the product.

Nonlinear finite element analysis of reinforced concrete structures subjected to transient thermal loads

  • Zhou, C.E.;Vecchio, F.J.
    • Computers and Concrete
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    • v.2 no.6
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    • pp.455-479
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    • 2005
  • This paper describes a 2D nonlinear finite element analysis (NLFEA) platform that combines heat flow analysis with realistic analysis of cracked reinforced concrete structures. The behavior models included in the structural analysis are mainly based on the Modified Compression Field Theory and the Distributed Stress Field Model. The heat flow analysis takes into account time-varying thermal loads and temperature-dependent material properties. The capability of 2D nonlinear transient thermal analysis is then implemented into a nonlinear finite element analysis program VecTor2(C) for 2D reinforced concrete membranes. Analyses of four numerical examples are performed using VecTor2, and results obtained indicate that the suggested nonlinear finite element analysis procedure is capable of modeling the complete response of a concrete structure to thermal and mechanical loads.

An Evaluation of the Effect of Internal Thinning Defect on the Failure Pressure of Elbow (곡관의 손상압력에 미치는 내부 감육결함의 영향 평가)

  • Kim, Jin-Weon;Kim, Tae-Soon;Park, Chi-Yong
    • Journal of the Korean Society of Safety
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    • v.18 no.4
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    • pp.28-34
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    • 2003
  • In the present study, three-dimensional finite element analysis was performed to investigate the effects of internal wall thinning defect on the failure pressure of elbow in the piping system and to develop the failure pressure evaluation model. From the results of finite element analysis, the failure pressure was derived by employing local stress criteria, and the effects of thinning location, bend radius, and defect geometry on the failure pressure of internally wall thinned elbow were investigated. Also, based on these investigations and previous model developed to estimate the failure pressure of elbow with an external pitting defect, the failure pressure evaluation model to be applicable to the elbow containing an internal thinning defect was proposed and compared with the results of finite element analysis. The failure pressure calculated by the model agreed well with the results of finite element analysis.