• Title, Summary, Keyword: 유한요소 접촉해석

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Numerical Simulation of Contact Duration in the Tapping Test of the Composite Structure (복합재료 구조물의 태핑 검사시 접촉시간의 수치 모사)

  • 황준석;김승조
    • Proceedings of the Korean Society For Composite Materials Conference
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    • pp.215-218
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    • 2001
  • 태핑 검사법을 이용한 복합재료 구조물의 손상검사 과정을 수치해석을 이용하여 모사하였다. 타격체에 의한 태핑을 모사하기 위해 동적접촉 알고리듬을 이용한 유한요소법을 이용하였다. 손상의 유무를 판별하는데 사용되는 척도로서 타격체와 구조물의 접촉하중의 시간이력을 계산하였다. 손상이 없는 복합재료 평판과 층간 분리 손상이 있는 복합재료 평판에 대한 해석을 통하여 접촉특성의 변화를 고찰하였다. 또한 태핑 검사법의 민감도에 대한 해석도 수행하였다.

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An Analysis of High Speed Forming Using the Explicit Time Integration Finite Element Method(II) - Application to High Speed Rolling - (엑스플리시트 시간 적분 유한 요소법을 이용한 고속 성형 해석(II) - 고속 압연 해석)

  • 유요한;정동택
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.5
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    • pp.1551-1562
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    • 1991
  • 최근까지 발표된 유한 요소법을 이용한 압연 해석 관련 주요 논문들을 정리해 보면 다음과 같다. Li와 Kobayashil는 강소성 유한 요소법(rigidplastic finite element method)을 여러가지 마찰조건에 대하여 해석하였다. 이때 압연롤은 강체 (rigid body)로 시편은 가공경화(workhardening)를 동반한 강소성체로 모델링하였다. Hwang과 Kobayashi는 강소성 유한 요소법을 이용한 평면 변형 압연에서 재료 손실을 최소화하는 예비 성형체(preform)의 설계에 대한 연구를 수행하였다. 이 경우에도 역시 압연롤은 강체로 시편은 가공 경화를 동반한 강소성체와 완전 소성체로 모델링 되었으나, 고착(sticking) 마찰 조건에 대해서만 해석을 수행하였다. Mori와 Osak- ada 그리고 Oda는 약간 압축성이 있는 재료의 평면 변형 압연에 대하여 연구하였다. 이때 압연롤은 강체로 시편은 가공 경화를 동반한 강소성체로 모델링 되었으며 경계 면에서는 Coulomb 마찰을 고려하였다. 이밖에도 오일러(Eulerian) 수식화를 이용한 Dawson과 Thompson, Berman의 해석 결과가 있으며, 또 폭 방향의 변형까지를 고려한 Li와 Kobayashi, Mori와 Osakada의 3차원 해석 결과가 있다.

A Finite Element Analysis of Elastomeric O-ring Performance and Structure when subjected to Foreign Objects (유한요소해석을 이용한 이물질이 고무오링과 구조물에 미치는 영향과 성능 연구)

  • Pack, Inseok;Rhee, Heejang;Lee, Seoksoon
    • Journal of Aerospace System Engineering
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    • v.11 no.1
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    • pp.28-34
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    • 2017
  • Elastomeric o-ring performance and structure when subjected to a foreign object is studied using finite element analysis (FEA). Elastomeric o-rings have been studied using 2D analysis for a long time. Contact pressure is an important factor in o-ring design. When contact pressure is lower than applied pressure, leaking, vibration, and noise can occur; resulting in decreased output. In this study, we compared 2D and 3D analyses of elastomeric o-rings. Similar results were shown for 2D and 3D contact pressure. However, when an o-ring encounters foreign object matter, 3D analysis is required because contact pressure in every direction needs to be considered. We determined the influence of foreign matter on o-ring performance and structure by analyzing 10 cases with different clearances in a 3D model. Therefore, an o-ring encountering foreign object matter must be analyzed in 3D with the result included in the o-ring design.

Analysis of Non-contacted type Blocking filter for Power Line Communication by using FEM (전자장 수치해석을 이용한 전력선 통신용 비접촉식 Blocking Filter 해석)

  • Han, Sang-Joon;Park, Il-Han;Kim, Byung-Sung;Lee, Se-Hee;Byun, Jin-Kyu;Nah, Wan-Soo
    • Proceedings of the KIEE Conference
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    • pp.110-112
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    • 2001
  • 본 논문에서는 전력선 통신 시스템의 전송신호가 비수용가로 전송되는 현상을 차단하기 위한 비접촉식 Blocking Filter를 유한요소법을 이용하여 해석하였다. 새로운 통신망 시스템이 연구되면서 기존의 전력케이블 망을 이용한 전력선 통신방식에 대한 연구가 이루어 졌으나, 전력선 통신이 서비스 지역 이외에 다른 지역으로 통신신호들이 전송될 수 있는 문제점이 제기되었으며, 또한 지정된 지역 내에서 최적화된 통신환경의 구성이 요구되었다. 따라서 본 논문은 타 지역으로의 신호 간섭을 차단하기 위한 비접촉식 Blocking Filter의 기본 모델을 제시하였으며, 이러한 비접촉식 Blocking Filter를 유한요소법을 기초로 한 전자장 수치해석 기법과 전송선 이론을 도입하여 신호 전송 특성을 해석하였다.

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Analysis of the Current-Collection Performance of a High-Speed Train Using Finite Element Analysis Method (유한 요소 해석 기법을 이용한 고속 철도 차량의 집전 성능 해석)

  • Jung, Sung-Pil;Park, Tae-Won;Kim, Young-Guk;Park, Chan-Kyoung;Paik, Jin-Sung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.7
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    • pp.827-833
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    • 2011
  • In this study, a simulation model to estimate the current-collection performance of a high-speed train was developed by using a commercial finite element analysis software, SAMCEF. A three-dimensional springDdamperDmass model of a pantograph was created, and its reliability was validated by comparing the receptance of the model to that of the actual pantograph. The wave propagation speed of the catenary model was compared with the analytical wave propagation speed of the catenary system presented in the UIC 799 OR standard. The length of the droppers was controlled, and the pre-sag of the contact wire due to gravity was considered. The catenary and the pantograph were connected by using a contact element, and the contact force variation when the pantograph was moved at velocities of 300 km/h and 370 km/h was obtained. The average, standard deviation, maximum, and minimum values of the contact force were analyzed, and the effectiveness of the developed simulation model was examined.

Design of Vertical Type Probe Tip Using Finite Element Analysis (유한요소해석을 이용한 수직형 프로브 팁의 설계)

  • Oh, Young-Ryun;Kim, Yun-Jae;Nam, Hyun-Suk;Park, Ung-Gi;Lee, Hak-Joo;Kim, Jung-Yub;Park, Jun-Hyub
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.8
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    • pp.851-856
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    • 2012
  • The design process of a micro-probe tip is very complicated and expensive. To avoid these problems, in this study, we used element (FE) analysis. To simplify design process. A new pre-probe tip (cobra-needle type) made of Ni and Co was designed by FE analysis. Experimental results were compared with those obtained by FE analysis to verify the reliability of the analysis. The contact force and over drive were respectively found to be 12.5 gf(Contact Force) and $100{\mu}m$(Over drive). We propose the new designed probe tip. Material of new designed probe tip is NiCo. Values of Property are 1~2 gf(Contact Force) and $100{\mu}m$(Over drive).

Stress Analyses of the Gimbal Bellows for a Lox Pipe (산화제 배관 김발 주름관 응력 해석)

  • Yoo, Jae-Han;Moon, Il-Yoon;Lee, Soo-Yong
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • pp.477-480
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    • 2011
  • The stress analyses of the 'U'-shaped multi-ply reinforced gimbal bellows under high pressure and rotational displacement loadings are performed at the room and cryogenic temperatures. The bellows are used for the Lox pipe line which connects the combustion chamber with the turbopump of a liquid rocket engine. The distributions of the stress, the strains and the contact pressures are obtained from the finite element analysis considering the geometric non-linearities of the contacts between the plies and the material one of the isotropic plasticity. Those are compared with the stress results from EJMA (Expansion Joint Manufacturing Association) standard. Also, the effects of the operating temperature and the reinforcing ring on the stresses are investigated.

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Analysis of low-velocity impact on composite sandwich panels using an assumed strain solid element (가정변형률 솔리드 요소를 이용한 복합재 샌드위치 평판의 저속충격 해석)

  • Park, Jung;Park, Hoon-Cheol;Yoon, Kwang-Joon;Goo, Nam-Seo;Lee, Jae-Hwa
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.30 no.7
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    • pp.44-50
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    • 2002
  • Low-velocity impact on composite sandwich panel has been investigated. Contact force is computed from a proposed modified Hertzian contact law. The Hertzian contact law is constructed by adjusting numerical value of the exponent and reducing the through-the- thickness elastic constant of honeycomb core. The equivalent transverse elastic constant is calculated from the rule of mixture. Nonlinear equation to calculate the contact force is solved by the Newton-Raphson method and time integration is done by the Newmark-beta method. A finite element program for the low-velocity impact analysis is coded by implementing these techniques and an 18-node assumed strain solid element. Behaviors of composite sandwich panels subjected to low-velocity impact are analyzed for various cases with different geometry and lay-ups. It has been found that the present code with the proposed contact law can predict measured contact forces and contact times for most cases within reasonable error bounds.

Investigation of Electromagnetic Force for Magnetic Contactor of Railway Vehicles (철도차량용 전자접촉기 전자코일의 전자기력 특성 연구)

  • Jung, Jooyoung;Park, Ji-Won;Choi, Jinnil
    • Journal of the Korean Society for Railway
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    • v.19 no.3
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    • pp.324-330
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    • 2016
  • A magnetic contactor is a switching device widely used for electric circuits. For the operation of magnetic contactors, magnetic coils are essential; these coils create and interrupt the electric circuit. In this paper, the finite element analysis model was developed to reflect the experimental data, and was verified through alteration of the applied voltages and the numbers of turns. Effects of electromagnetic force on the geometrical variations of the facing poles for fixed and moving cores of two magnet coils were investigated. In addition, effects of slope and air gap size between two facing poles on the electromagnetic force were explored through the distribution of the magnetic flux density in the magnetic coils of a push-type solenoid. Through this analysis, the characteristics of the electromagnetic force against the facing poles were explored.

Thermoelastic Contact Analysis of Drum Brakes by Finite Element Method (유한요소법에 의한 드럼 브레이크의 열탄성 접촉해석)

  • Seo, Jung-Won;Goo, Byeong-Choon
    • Proceedings of the KSME Conference
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    • pp.381-386
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    • 2000
  • The brake force of drum brakes for commercial vehicles is applied by a s-cam. First of all the influence of the s-cam load angles and elastic modulus of the pad on the contact pressure distribution between pad and drum was checked by using 3 dimensional finite element model. In the second part, temperature and thermal stress analyses were carried out by an axisymmetric model with constant heat flux and pressure-proportional heat flux. In the case of temperature analysis the heat conduction from the interface to the pad and the drum was modeled using a thin soft film element, so artificial division of the generated heat flux between pad and drum is not necessary. The analysis was performed by ABAQUS/Standard code.

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