• 제목/요약/키워드: Force Evaluation

검색결과 2,074건 처리시간 0.027초

유한요소 해석을 통한 코트 스포츠화의 런닝시 충격력 평가 (Evaluation of Landing Impact Force of Court Sport Shoes at Running by Finite Element Analysis)

  • 김성호;조진래;류성헌;최주형
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.498-503
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    • 2004
  • A fundamental function of court sport shoes has been considered as the protection of human feet from unexpected injuries. But, recently its role for improving the playing competency is being regarded as a more important function. In connection with this situation, intensive efforts are being world-widely forced on the development of court sport shoes proving the excellent playing competency, by taking kinesiology and biomechanics into consideration. However, the success of this goal depends definitely on the shoes design based upon the reliable evaluation of shoes functional parts. This paper addresses the application of finite element method to the evaluation of landing impact force of court sport shoes. In order to reflect the coupling effect between leg and shoes accurately and effectively, we construct a fully coupled shoes-leg FEM model which does not rely on the independent experimental data any more. Through the numerical experiments, we assess the reliability of the coupled FEM model by comparing with the experimental results and investigate the landing impact characteristics of court sport shoes.

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유한요소법을 이용한 코트 스포츠화의 착지 충격력 평가 (Evaluation of Landing Impact Force of Court Sport Shoes by Finite Element Method)

  • 김성호;류성헌;최주형;조진래
    • 대한기계학회논문집A
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    • 제28권11호
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    • pp.1786-1793
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    • 2004
  • A fundamental function of court sport shoes was considered as the protection of human feet from unexpected injuries. But, recently its role for improving the playing competency has been regarded as of more importance. In connection of this situation, intensive efforts are world-widely forced on the development of court sport shoes proving the excellent playing competency by taking kinesiology and biomechanics into consideration. However, the success of this goal depends definitely on the shoes design based upon the reliable evaluation of shoes functional parts. This paper addresses the application of finite element method to the evaluation of landing impact force of court sport shoes. In order to reflect the coupling effect between leg and shoes accurately and effectively, we construct a fully coupled shoes-leg FEM model which does not rely on the independent experimental data any more. Through the numerical experiments, we assess the reliability of the coupled FEM model by comparing with the experimental results and investigate the landing impact characteristics of court sport shoes.

항자력과 자기포화도에 의한 WC-8%Co 초경합금의 기계적 성질 평가 (The Evaluation of Mechanical Property of WC-8%Co Alloys by Coercive Force and Magnetic Saturation)

  • 안동길
    • 비파괴검사학회지
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    • 제20권5호
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    • pp.438-444
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    • 2000
  • WC-Co 초경합금의 항자력과 자기포화도를 평가하여 합금조직과 이에 따른 기계적 성질의 예측에 관해 연구하였다. WC 입경이 다르고 탄소함량 및 소결온도가 다른 WC-8%-Co 초경합금을 분말 야금법에 의해 제조하였다. 항자력과 자기포화도와 같은 WC-Co 합금의 자기적 특성은 합금조성 및 조직에 크게 의존하였다. 미소한 합금탄소량의 변화와 WC 입도의 차이에 의해서도 WC-Co 합금의 자기적 특성과 경도 및 항절력이 크게 변화하였다. WC 입도가 미세할수록 소결합금의 항자력과 경도는 증가하였고, 항자력은 경도의 증가와 비례하였다. WC-8%Co 합금의 화학 양론적 조성 아래로 카본함량이 감소하면 자기포화도와 항절력이 떨어지고 $\eta$상의 체적률도 꾸준히 증가하였다. WC-Co 합금에 있어서 자기포화도는 항자력과 반비례하였다.

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젤리의 기계적 및 관능적 물성 (Instrumental and Sensory Characteristics of Jelly)

  • 이태휘;이윤형;유명식;이규순
    • 한국식품과학회지
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    • 제23권3호
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    • pp.336-340
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    • 1991
  • 시판되고 있는 7종의 젤리를 가지고 rheometer를 사용하여 저작실험을 한 결과 관능적 물성인 hardness 및 shortness와 가장 상관제수가 높은 기계적 물성은 maximum force로서 2900-3136($10^3\;dyne$) 범위에서 적당하다고 나타났으며 또한 stickiness는 adhesiveness force와 관능적인 물성 springiness는 기계적 물성값 springiness로 예측할 수 있었다. 그러나 종합평가와의 회귀식에서 얻은 적당하다고 계산된 값과는 약간의 차이를 나타내었으며 특히 종합평가와 결정계수가 가장 높은 기계적 물성은 cohesiveness이었다. 종합평가와 각 기계값과의 관계에서 종합평가에 가장 영향을 미치는 기계값은 cohesiveness, adhesiveness force로 이들의 결정계수는 각각 0.93, 0.89이었으며 종합평가를 종속변수로 하고 cohesiveness 및 adhesiveness를 독립변수로 하여 multiple linear regression 한 결과 종합평가=2.70+6.25(cohesiveness) -0.095(adhesiveness)의 상관식을 얻었으며 이 때의 중상관계수 0.94이었다.

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COMPUTATION OF THE DYNAMIC FORCE COMPONENT ON A VERTICAL CYLINDER DUE TO SECOND ORDER WAVE DIFFRACTION

  • Bhatta, Dambaru
    • Journal of applied mathematics & informatics
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    • 제26권1_2호
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    • pp.45-60
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    • 2008
  • Here we consider the evaluation of the the dynamic component of the second order force due to wave diffraction by a circular cylinder analytically and numerically. The cylinder is fixed, vertical, surface piercing in water of finite uniform depth. The formulation of the wave-structure interaction is based on the assumption of a homogeneous, ideal, incompressible, and inviscid fluid. The nonlinearity in the wave-structure interaction problem arises from the free surface boundary conditions, namely, dynamic and kinematic free surface boundary conditions. We expand the velocity potential and free surface elevation functions in terms of a small parameter and then consider the second order diffraction problem. After deriving the pressure using Bernoulli's equation, we obtain the analytical expression for the dynamic component of the second order force on the cylinder by integrating the pressure over the wetted surface. The computation of the dynamic force component requires only the first order velocity potential. Numerical results for the dynamic force component are presented.

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Biomechanical Analysis with the Force of Deltoid Muscle for Pianist

  • Shin, Dong-Ok;La, Seung-Houn
    • International Journal of Safety
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    • 제4권1호
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    • pp.27-31
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    • 2005
  • This study presents the relationship between the height of the chair and the force of deltoid muscle for pianist. The subject simulated playing the piano on the three different heights of the chairs. Digital camera was used to determine the angle of the joint of shoulder and elbow for 2-dimensional static link segment modeling in the sagittal plane. The deltoid, biceps and triceps muscles were considered to determine the muscle load. The results, compared to the force of deltoid muscle, are that the downward position of the higher chair produces significantly large force than the other two lower chairs. It can be caused by hunched shoulder with decreasing deltoid angle. In case of the upward position caused by the lower chair, even though the smallest force of deltoid presented, it was increased the force of elbow.

통신 교환기 고밀도 접속용 탄성 압입 핀의 특성 평가 (Evaluation of Complaint Press-Fit pin for Telecommunications)

  • 신동필;정명영;홍성인
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 추계학술대회논문집A
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    • pp.481-485
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    • 2000
  • A new type of compliant press-fit pin has been developed and evaluated for use packaging of electronic telecommunications equipments. Main requirements for design are defined the upper limit of pin insertion force and the lower limit of pin retention force. Upper limit of pin insertion force is set to protect the copper plate of the inner PTH wall. Lower limit of pin retention force is set to satisfy a wire-wrapping specification. Results are represented by insertion force and retention force variations according to the front angle, rear angle and material, etc.

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가솔린 기관의 피스톤-링 결합체 마찰력 측정에 관한 실험적 연구 (An experimental study on friction measurement of piston-ring assembly of a SI engine)

  • 이동원;윤정의;김승수
    • 오토저널
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    • 제12권4호
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    • pp.66-74
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    • 1990
  • Friction between piston-ring assembly and cylinder wall of a spark ignition engine was evaluated under various engine operating conditions utilizing a grasshopper linkage system. The friction force was estimated by the force balance relation at the small end of connecting rod. Three forces were chosen to be measured for the objective. They were gas pressure inside the cylinder, inertia force of the piston-ring assembly, and the force exerted by the connecting rod. These forces were measured by a piezo type pressure sensor, an accelerometer and strain gauges, respectively. Comparisons were made with the frictional force evaluated by the conventional method where the assumption of constant rotational speed of engines was adopted. Due to the variation of rotational speed of engines, the conventional method was found to lead to a large error in the evaluation of the frictional force.

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3축 로드 시뮬레이터 링크부의 메카니즘 설계 (A Mechanism Design of the 3-axial Road Simulator Linkage)

  • 정상화;류신호;김종태;이규태;장완식
    • 한국자동차공학회논문집
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    • 제11권2호
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    • pp.140-147
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    • 2003
  • Full scale durability test in the laboratory is an essential of any fatigue life evaluation of components or structures of the automotive vehicle. Component testing is particularly important in today's highly competitive industries where the design to reduce weight and production costs must be balanced with the necessity to avoid expensive service failure. Generally, hydraulic road simulator is used to carry out the fatigue test and the vibration test. In this paper, the link unit which is able to realize the 3 element forces such as vertical force, lateral force, and longitudinal force that are applied to the road simulator is designed. Also, the designed link is verified with kinematics and inverse-kinematics. From this results, the designed factor satisfied the maximum stroke so that it satisfied the requirements for 3-axial road simulator.

고속철도 교량상의 장대레일 축력 해석 (Longitudinal Force Analysis of CWR on High Speed Rail Bridges)

  • 이지하;양신추;이종득
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 1998년도 창립기념 춘계학술대회 논문집
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    • pp.556-563
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    • 1998
  • Railway bridges have a significant effect on the stress and displacement of continuous welded rail(CWR). Longitudinal compression force at high temperature, combined breaking or acceleration forces can introduce track buckling. On the other hand, longitudinal tensile forces, associated with low temperatures, in combination with breaking forces may break rail. Therefore, it is very important to work out thorough counter measures for those problems, specially in high speed rail which high safety is required. The exact evaluation of longitudinal force of rail has the key to the solution. The main aim of the present paper is to examine whether the longitudinal force of CWR's on Kyung-Bu-HSR satisfy the criteria to be fulfilled in the design of railway bridge. The analyses are carried out by using "CWRAP" program which was developed by our research group. The ballast resistance and breaking force effects on the longitudinal force of CWR are investigated.

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