• Title/Summary/Keyword: von-mises

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THE EFFECTS OF MESH STYLE ON THE FINITE ELEMENT ANALYSIS FOR ARTIFICIAL HIP JOINTS

  • Shin, Jae-Min;Lee, Dong-Sun;Kim, Sung-Ki;Jeong, Da-Rae;Lee, Hyun-Geun;Kim, Jun-Seok
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.15 no.1
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    • pp.57-65
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    • 2011
  • In this paper, a good quality mesh generation for the finite element method is investigated for artificial hip joint simulations. In general, bad meshes with a large aspect ratio or mixed elements can give rise to excessively long computational running times and extremely high errors. Typically, hexahedral elements outperform tetrahedral elements during three-dimensional contact analysis using the finite element method. Therefore, it is essential to mesh biologic structures with hexahedral elements. Four meshing schemes for the finite element analysis of an artificial hip joint are presented and compared: (1) tetrahedral elements, (2) wedge and hexahedral elements, (3) open cubic box hexahedral elements, and (4) proposed hexahedral elements. The proposed meshing scheme is to partition a part before seeding so that we have a high quality three-dimensional mesh which consists of only hexahedral elements. The von Mises stress distributions were obtained and analyzed. We also performed mesh refinement convergence tests for all four cases.

Analysis of Deflection of Reinforced Concrete Flexural Members under Monotonic Loading (단조하중을 받는 철근콘크리트 휨부재의 처짐해석)

  • Byun, Keun Joo;Kim, Young Jin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.11 no.1
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    • pp.69-78
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    • 1991
  • This paper concentrates on the analysis of deflection of the reinforced concrete flexural members under monotonic loading. Concrete is treated as an orthotropic nonlinear material. The concept of equivalent strain and crack strain are used to establish independent stress-strain relationships in the directions of orthotropy. Steel is modeled as an elstoplastic material, and von Mises failure criterion is applied. The finite element computer program for the nonlinear analysis of the deflection of RC flexural members under monotonic loading is developed. The accuracy and reliability of the numerical procedure is demonstrated by the FEM analysis and experiments of the under reinforced concrete beams over the entire loading range up to failure.

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Seismic Performance Evaluation of Curved Bridges by Gyeong-Ju Earthquakes (경주지진에 의한 곡선교량의 내진 안전성 평가)

  • Jeon, Jun-Tai
    • Journal of the Society of Disaster Information
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    • v.14 no.1
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    • pp.43-50
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    • 2018
  • This study presented 3D Finite Element (FE) analysis of curved beam structures subjected to static and dynamic loading conditions, which is particularly strong ground motions. It was shown that the results obtained from 3D FE analyses was similar to the theoretical solution within 1% convergency error, in order to validate the 3D solid FE models in this study. In particular, it was focusing on development of dynamic characteristics of curved beam structures subjected to three-different seismic ground motions: GyeongJu, Lomaprieta and Northridge earthquakes. Consequently, It was interesting to find that the results obtained from GyeongJu earthquake was detuned due to high frequency effect, but the Von-Mises of the curved beam structure under Lomaprieta earthquake was 647.824 MPa at 45 curvature degree.

Undrained Analysis of Soft Clays Using an Anisotropic Hardening Constitutive Model: II. Numerical Analysis (비등방경화 구성모델을 적용한 연약 지반의 비배수 거동 해석 : II. 수치해석)

  • 오세붕
    • Journal of the Korean Geotechnical Society
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    • v.15 no.6
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    • pp.131-142
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    • 1999
  • The objective of this study is to perform finite element analyses using the anisotropic hardening constitutive model on the basis of the total stress concept. An anisotropic hardening constitutive model had been developed in a companion paper, and was then formulated by implicit stress integration and consistent tangent moduli. A nonlinear finite element analysis program was coded including the algorithm, and as a result, the nonlinear solution was accurately calculated and converged to be asymptotically quadratic. In the analysis of a test embankment it was found that the proposed model could predict the displacement of soils more reasonably than the analysis with von Mises type model. In addition the proposed model could predict accurately the actual behavior through the reanalysis of the problem by a reasonable evaluation of the strength parameter.

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Nonparametric homogeneity tests of two distributions for credit rating model validation (신용평가모형에서 두 분포함수의 동일성 검정을 위한 비모수적인 검정방법)

  • Hong, Chong-Sun;Kim, Ji-Hoon
    • Journal of the Korean Data and Information Science Society
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    • v.20 no.2
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    • pp.261-272
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    • 2009
  • Kolmogorov-Smirnov (K-S) statistic has been widely used for testing homogeneity of two distributions in the credit rating models. Joseph (2005) used K-S statistic to obtain validation criteria which is most well-known. There are other homogeneity test statistics such as the Cramer-von Mises, Anderson-Darling, and Watson statistics. In this paper, these statistics are introduced and applied to obtain criterion of these statistics by extending Joseph (2005)'s work. Another set of alternative criterion is suggested according to various sample sizes, type a error rates, and the ratios of bads and goods by using the simulated data under the similar situation as real credit rating data. We compare and explore among Joseph's criteria and two sets of the proposed criterion and discuss their applications.

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Finite element stress analysis on supporting bone by tripodal placement of implant fixture (유한요소법을 이용한 임플란트 고정체의 삼각배열에 따른 지지골의 응력 분석)

  • Son, Sung-Sik;Lee, Myung-Kon
    • Journal of Technologic Dentistry
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    • v.31 no.1
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    • pp.7-15
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    • 2009
  • Purpose: This study was to propose the clear understanding for stress distribution of supporting bone by use of staggered buccal offset tripodal placement of fixtures of posterior 3 crown implant partial dentures. We realized posterior 3 crown implant fixed partial dentures through finite element modeling and analysed stress effect of implant arrangement location to supporting bone under external load using finite element method. Method: To understand stress distribution of 3 crown implant fixed partial dentures which have 2 different arrangement by finite element analysis. In each model, for loading condition, we applied $45^{\circ}$ oblique load to occlusal surface of crown and applied 100 N for 3 crown individually(total 300 N) for imitating possible oral loading condition. at this time, we calculated Von Mises stress distribution in supporting bone through finite element method. Result: When apply $45^{\circ}$ oblique load to in-line arrangement model, maximum stress result for 100 N for each 3 crown 47.566MPa. In tripodal placement, result for 1mm buccal offset tripodal placement implant model was maximum distributed load 51.418MPa, so result was higher than in-line arrangement model. Conclusion: In stress distribution result by placement of implant fixture, the most effective structure was in-line arrangement. The tripodal placement does not effective for stress distribution, gap cause more damage to supporting bone.

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