• Title/Summary/Keyword: System Rigidity

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Coupled Transverse Vibrations of Propeller-Shaft Systems (추진축계(推進軸系)의 연성횡진동(聯成橫振動)에 관(關)하여)

  • Si-Young,Ahn
    • Bulletin of the Society of Naval Architects of Korea
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    • v.22 no.1
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    • pp.38-44
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    • 1985
  • A computer program was developed for the analysis of the coupled transverse vibrations of a multi-supported shaft system. The program, based on the theory of Transfer Matrix Method, was written including the system parameters such as the entrained water and gyroscopic effects of the propeller, the rigidity of bearing combined with the oil film effect, and the whirling frequency of the shaft. The program was used to calculate the resonance frequency of the shafting system of the ship Hanbada. The results show good agreement with the measured values. The results are also compared with those of F.E.M. from the comparison, it is found that both results agree well with each other.

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A Structural Flexible Behavior T-type Joint for RCS Composite System (철근콘크리트기둥과 철골보 접합부의 휨성능(1))

  • Kim, Young-Soo;Kim, Young-Ho;Jeong, Jae-Hun;Kim, Jin-Mu;Won, Young-SuI;Joo, Kyung-Jai
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.5 no.4
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    • pp.139-146
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    • 2001
  • Res system, with Reinforced Concrete columns and Steel beams, is defined as system in which both steel and concrete materials are efficiently combined to maximize the structural and economic advantages of each material. Tested in this study were 4 exterior beam-to-column joint specimens with variables that influence joint rigidity of RCS structure. The purpose of this study is to compare and analyze the structural behavior of exterior joints through the existing studies and tests, and offer basic data for practical use of RCS structure by studying flexible behavior(semi-rigid effect) of joints according to joint details.

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Nonlinear Behaviors of Cable Spoke Wheel Roof Systems (케이블 스포크 휠 지붕 시스템의 비선형 거동)

  • Park, Kang-Geun;Lee, Mi-Hyang;Park, Mi-Jin
    • Journal of Korean Association for Spatial Structures
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    • v.17 no.1
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    • pp.31-40
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    • 2017
  • The objective of this study is to analysis the mechanical characteristics and nonlinear behaviors on the geometric nonlinear behavior of a cable spoke wheel roof system for long span lightweight roof structures. The weight of a cable spoke wheel roof dramatically can reduce and the cable roof system can easily make the required rigidity and shape by the sag ratio and pretension forces. Determining the pretension and initial sag of cable roof system is essential in a design process and the shape of roof is changed by pretension. The nonlinear behavior of flexible cable system has greatly an affect on the sag and pretension. This paper will be carried out analyzing and comparing the tensile forces and deflection of a cable spoke wheel system for the large span retractable roof, and analyzed to deflections and tensile forces by the post height of center hub. The double arrangement of a spoke wheel system with reverse curvature works more effectively as a load bearing system, the pretension can easily increase the structural stiffness. The cable truss system can carry vertical load in up and downward direction, and act effectively as load bearing elements.

Parametric analysis of hybrid outrigger system under wind and seismic loads

  • Neethu Elizabeth Johna;Kiran Kamath
    • Structural Engineering and Mechanics
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    • v.86 no.4
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    • pp.503-518
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    • 2023
  • In tall constructions, the outriggers are regarded as a structural part capable of effectively resisting lateral loads. This study analyses the efficacy of hybrid outrigger system in high rise RCC building for various structural parameters identified. For variations in α, which is defined as the ratio of the relative flexural stiffness of the core to the axial rigidity of the column, static and dynamic analyses of hybrid outrigger system having a virtual and a conventional outrigger at two distinct levels were conducted in the present study. An investigation on the optimal outrigger position was performed by taking the results from absolute maximum inter storey drift ratio (ISDmax), roof acceleration (accroof), roof displacement (disproof), and base bending moment under both wind and seismic loads on analytical models having 40, 60 and 80 storeys. An ideal performance index parameter was introduced and was utilized to obtain the optimal position of the hybrid outrigger system considering the combined response of ISDmax, accroof, disproof and, criteria required for the structure under wind and seismic loads. According to the behavioural study, increasing the column area and outrigger arm length will maximise the performance of the hybrid outrigger system. The analysis results are summarized in a flowchart which provides the optimal positions obtained for each dependent parameter and based on ideal performance index which can be used to make initial suggestions for installing a hybrid outrigger system.

Numerical Stress Analysis of bone plate System using 3-dimensional finite element method (3차원 유한 요소법을 이용한 골절판의 응력 해석)

  • Kim, Hyun-Su;Kwon, Young-Soo
    • Proceedings of the KOSOMBE Conference
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    • v.1991 no.05
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    • pp.74-78
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    • 1991
  • Conventional compression bone fracture plates sometimes cause osteoporosis under the plate due to their high rigidity which in turn transfer physiological load mostly through the plates and screws. In order to prevent the osteopenia we have designed a system which have a viscoelastic washer between plate and screw head. The washer is made of a biocompatible ploymer (untra high molecular weight polyethylene, UHMWPE). Three-dimensional finite element meshes of the human femur with the conventional and new concept bone plate ere generated and the comparative stress analyses are performed with static half-stance loading condition. The results of analyses showed that could reduce the stress shielding effect compared with the conventional plate.

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Rigidity and Vibration Analysis on Fiber-Reinforced Composite Corrugated Plates (섬유 강화형 복합재료 주름판의 강성 및 진동 해석)

  • Chung, Kang;Kim, Young-Wann
    • Composites Research
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    • v.15 no.4
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    • pp.1-8
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    • 2002
  • In this study, the rigidities of fiber-reinforced composite corrugated plates are derived to achieve the weight reduction, high strength, and high stiffness. The vibration of the corrugated plates for all the conventional boundary conditions in the plates is analyzed numerically by applying the derived rigidities, and so the analysis system is programmed to obtain the results by using Visual Basic language. Consequently, the characteristics of fiber-reinforced composite corrugated plates can be easily investigated from the results provided by the programmed system.

Soil-structure interaction analysis of beams resting on multilayered geosynthetic-reinforced soil

  • Deb, Kousik
    • Interaction and multiscale mechanics
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    • v.5 no.4
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    • pp.369-383
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    • 2012
  • In this paper, soil-structure interaction analysis has been presented for beams resting on multilayered geosynthetic-reinforced granular fill-soft soil system. The soft soil and geosynthetic reinforcements are idealized as nonlinear springs and elastic membranes, respectively. The governing differential equations are solved by finite difference technique and the results are presented in non-dimensional form. It is observed from the study that use of geosynthetic reinforcement is not very effective for maximum settlement reduction in case of very rigid beam. Similarly the reinforcements are not effective for shear force reduction if the granular fill has very high shear modulus value. However, multilayered reinforced system is very effective for bending moment and differential settlement reduction.

Actin Engine in Immunological Synapse

  • Piragyte, Indre;Jun, Chang-Duk
    • IMMUNE NETWORK
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    • v.12 no.3
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    • pp.71-83
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    • 2012
  • T cell activation and function require physical contact with antigen presenting cells at a specialized junctional structure known as the immunological synapse. Once formed, the immunological synapse leads to sustained T cell receptor-mediated signalling and stabilized adhesion. High resolution microscopy indeed had a great impact in understanding the function and dynamic structure of immunological synapse. Trends of recent research are now moving towards understanding the mechanical part of immune system, expanding our knowledge in mechanosensitivity, force generation, and biophysics of cell-cell interaction. Actin cytoskeleton plays inevitable role in adaptive immune system, allowing it to bear dynamic and precise characteristics at the same time. The regulation of mechanical engine seems very complicated and overlapping, but it enables cells to be very sensitive to external signals such as surface rigidity. In this review, we focus on actin regulators and how immune cells regulate dynamic actin rearrangement process to drive the formation of immunological synapse.

Analysis of lever actuator for the optical disk (광 픽업용 레버 구동기의 해석)

  • 한창수;김수현
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.618-621
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    • 2001
  • The proposed lever actuator has no friction and mass balance characteristics in motion, which are adapt to high-speed and high-density optical disk system. This paper discussed about the theoretical analysis of the lever structure. The modeling of the lever actuator is found. Using the Newton's method, the motion of equation is deduced through the constraint equations and equilibrium equations in three directions (focusing, tracking and tilting). From the above analysis, we know that the shape of the hinge is the very important parameter on determining the performance of the lever actuator, and the actuator has the 2nd order system characteristics. And the first resonant frequency in transmissibility is dependent to the rigidity of the lever while the first transmissibility resonance of conventional actuators is dependent to the first natural resonance of those actuators. This means that the lever actuator is more stable to the external vibration.

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Buckling Analysis of Spherical Shells With Periodic Stiffness Distribution According to Shape Parameter (강성분포가 주기성을 갖는 구형쉘의 형상계수에 따른 좌굴해석)

  • Park, Sang-Hoon;Suk, Chang-Mok;Jung, Hwan-Mok;Kwon, Young-Hwan
    • 한국공간정보시스템학회:학술대회논문집
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    • 2004.05a
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    • pp.169-175
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    • 2004
  • Researches on spherical shell which is most usually applied have been completed by many investigators already and generalized numerical formula was derived. But the existent researches are limited to those on spherical shell with isotropic or orthotropic roof stiffness, periodic distribution of roof stiffness that can be caused by spherical and latticed roof system is not considered. Therefore, this paper is to develop a structural analysis program to analyze spherical shells that have periodicity of roof stiffness distribution caused by latticed roof of large space structure, grasp buckling characteristics and behavior of structure.

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