• Title/Summary/Keyword: Force Distribution

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Response Force Distribution Factors of Members and Mutuality of Response Forces between Members (부재응력분포계수와 부재간 응력 상관성)

  • 김치경;이시은;홍건호
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2004.10a
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    • pp.363-370
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    • 2004
  • This Paper presents the response force distribution factor(RDF) and its application to recalculation of member forces in case of partial changes of structures. Using RDF, the mutuality of response forces between members can be estimated. The reanalysis technique recalculates directly any displacement or member force under consideration in real time without a full reanalysis in spite of local changes in member stiffness or connectivity using RDF. It is expected that RDF and the reanalysis technique can be used to develop efficient analysis techniques for tall buildings.

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다중 병렬판 구조의 변형률 분포해석

  • 김갑순;강대임;송후근;주진원
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.04a
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    • pp.585-590
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    • 1995
  • This paper describes strain distribution analysis of a multiple parallel plate structure for a multi-componenet force and moment sensor. A parallel plate structure which has higher rigidity than a simple beam structure are widely used for multi-component force and moment sensor. The strain distribution in the beams of a parallel plate structure should be accurately calculated to design a high precision multi-component force and moment sensor. We derived equations to calculate the strains for multiple parallel plate structure. It reveals that results from finite element analysis and experiment are in good agreement with results from the derived equations.

Optimal load distribution for two cooperating robot arms using force ellipsoid

  • Choi, Myoung-Hwan;Cho, Hye-Kyung;Lee, Bum-Hee;Ko, Myoung-Sam
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10b
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    • pp.1790-1795
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    • 1991
  • The optimal load distribution for two cooperating robots is studied in this paper, and a new solution approach utilizing force ellipsoid is proposed. The load distribution problem is formulated as a nonlinear optimization problem with a quadratic cost function. The limit on instantaneous power is considered in the problem formulation as the joint torque constraints. The optimal solution minimizing energy consumption is obtained using the concept of force ellipsoid and the nonlinear optimization theory. The force ellipsoid provides a useful geometrical insight into the load distribution problem. Despite the presence of the joint torque constraints, the optimal solution is obtained almost as a closed form, in which the joint torques are given in terms of a single scalar parameter that can be obtained numerically by solving a scalar equation.

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Position and Force Control for Two Robots with Application to Load Distribution (두 로보트의 위치 및 힘 제어의 부하분배에 관한 응용)

  • Kim, Kab-Il;Jeon, Hun-Jong;Kim, Dong-Jun
    • Proceedings of the KIEE Conference
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    • 1992.07a
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    • pp.414-416
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    • 1992
  • Stability analysis and load distribution problem of two coordinating robots using full dynamic model is studied in this paper. Dynamic models of two robots are combined with the position force control strategy and the Liapunov 2nd method is used for the proof of the stability. This analysis shows that the position and force control of two coordinating robot is always stable. Also, load distribution problem is mentioned with respect to the end-effector forces minimizing joint torques.

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The characteristics of the multi-span suspension bridge with double main cables in the vertical plane

  • Zhang, Li-Wen;Xiao, Ru-Cheng;Jiang, Yang;Chai, Sheng-Bo
    • Structural Engineering and Mechanics
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    • v.42 no.3
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    • pp.291-311
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    • 2012
  • The multi-span suspension bridge having double main cables in the vertical plane is investigated regarding endurance of live load distribution in the case of non-displaced pylon and pylon displacement. The coefficient formula of live load distribution described as the ratio of live load on the bottom cable to the top cable is obtained. Based on this formula, some function in respect of this bridge are derived and used to analyze its characteristics. This analysis targets the cable force, the cable sag and the horizontal displacement at the pylon top under live load etc. The results clarified that the performance of the live load distribution and the horizontal force of cables in the case of non-deformed pylon has a similar tendency to those in the case of deformed pylon, and the increase of pylon rigidity can increase live load distributed to the bottom cable and slightly raise the cable horizontal force under live load. However, effect on the vertical rigidity of bridge and the horizontal force increment of cables caused by live load is different in the case of non-deformed pylon and deformed pylon.

A Study on Effect on Current Density Distribution, Inductance Gradient, and Contact Force by Variation of Armature and Rail Structure (아마츄어 및 레일의 구조 변화에 따른 전류 밀도, 인덕턴스 경도 및 접촉력의 영향 연구)

  • 김복기
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.50 no.2
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    • pp.59-64
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    • 2001
  • The distribution of current in the conductors influenced by the armature geometry and velocity is an important parameter for determining performance of an electromagnetic launcher(EML). the electric current in the early launching stage tends to flow on the outer surfaces of the conductors, resulting in very high local electric current density. However, the tendency for current to concentrate on the surface is driven by the velocity skin effect later in launching stage. The high current density produces high local heating and, consequently, increases armature wear which causes several defects on EML system. This paper investigates the effects of rail/armature geometry on current density distribution, launcher inductance gradient (L'), and contact force. Three geometrical parameters are used here to characterize the railgun system. These are the ratio of contact length to root length, relative position of contact leading edge to root trailing edge, and the ratio of rail overhang to the rail height. The distribution of current density, L', contact force between various configurations of the armature and the rail are analyzed and compared by using the EMAP3D program.

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The effect of varying peripheral bone structure and bone density on the occlusal stress distribution of human premolar regions (사람 소구치부위에서 주위골의 구조 및 밀도변화가 교합력에 의한 치아의 응력분포에 미치는 영향)

  • Suh, Ye-Joon;Shim, June-Sung;Lee, Keun-Woo;Chung, Moon-Kyu;Lee, Ho-Yong
    • Journal of Dental Rehabilitation and Applied Science
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    • v.19 no.1
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    • pp.7-15
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    • 2003
  • This study used FEM(Finite Element method) based on micro-CT images to see the effects of occlusal force distribution with varying bone density and structure. the mandibular premolar region from human cadaver, thickness of 10mm was imaged using micro-CT. the cross sectional images were taken every $10{\mu}m$. these were reconstructed and the longitudinal image at the mid point of mesiodistal of the speciman was obtained for the specimen for the FEM. The stress disribution produced by a vertical force at 100N and 100N horizontal were analyzed by MSC Nastran FEM Package. according to the result of this study the occlusal force distribution depends on the structure of cancellus bone and for further information on the occlusal force distribution on the tooth and the surrounding structure requires further studies on cancellus bone structure. CEJ of all model show the highest peak and region whice meet teeth and bone show second high peak. Original model and cortical bone add model show different stress distribution. Stress distribution changed according to bone structures and densities.

Force-finding of Tensegrity Structure using Optimization Technique

  • Lee, Sang Jin
    • Architectural research
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    • v.17 no.1
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    • pp.31-40
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    • 2015
  • A simple force-finding process based on an optimization technique is proposed for tensegrity structures. For this purpose, the inverse problem of form-finding process is formulated. Therefore, the position vector of nodes and element connectivity information are provided as priori. Several benchmark tests are carried out to demonstrate the performance of the present force-finding process. In particular, the force density distributions of simplex tensegrity are thoroughly investigated with the important parameters such as the radius, height and twisting angle of simplex tensegrity. Finally, the force density distribution of arch tensegrity is produced by using the present force-finding process for a future reference solution.

Distribution of shear force in perforated shear connectors

  • Wei, Xing;Shariati, M.;Zandi, Y.;Pei, Shiling;Jin, Zhibin;Gharachurlu, S.;Abdullahi, M.M.;Tahir, M.M.;Khorami, M.
    • Steel and Composite Structures
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    • v.27 no.3
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    • pp.389-399
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    • 2018
  • A perforated shear connector group is commonly used to transfer shear in steel-concrete composite structures when the traditional shear stud connection is not strong enough. The multi-hole perforated shear connector demonstrates a more complicated behavior than the single connector. The internal force distribution in a specific multi-hole perforated shear connector group has not been thoroughly studied. This study focuses on the load-carrying capacity and shear force distribution of multi-hole perforated shear connectors in steel-concrete composite structures. ANSYS is used to develop a three-dimensional finite element model to simulate the behavior of multi-hole perforated connectors. Material and geometric nonlinearities are considered in the model to identify the failure modes, ultimate strength, and load-slip behavior of the connection. A three-layer model is introduced and a closed-form solution for the shear force distribution is developed to facilitate design calculations. The shear force distribution curve of the multi-hole shear connector is catenary, and the efficiency coefficient must be considered in different limit states.

An Improved Scheme for the Blank Holding Force in Sheet Metal Forming Analysis using the Modified Membrane Finite Element Considering Bending Effect (굽힘이 고려된 개량 박막 유한요소를 사용한 박판금속 성형해석에서의 블랭크 홀딩력 적용방법에 관한 연구)

  • Choi, Tae-Hoon;Huh, Hoon
    • Transactions of Materials Processing
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    • v.8 no.4
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    • pp.347-355
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    • 1999
  • The paper is concerned with an improved scheme for application of the blank holding force in order to take account of the thickness distribution in the sheet material of the flange region. The scheme incorporates with a modified membrane finite element method for planar anisotropic materials. The new scheme proposed two coefficients α and βto calculate the compressive stress in the sheet metal due to the blank holding force, which should be determined properly for accurate analysis. The effect of αand βon the blank holding force distribution and the deformed shape is investigated with simulation of rectangular cup deep drawing processes by changing parameter values.

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