• Title/Summary/Keyword: Hinge mechanism

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Equivalent Plastic Hinge Length Model for Flexure-Governed RC Shear Walls (휨 항복형 철근콘크리트 전단벽의 등가소성힌지길이 모델)

  • Mun, Ju-Hyun;Yang, Keun-Hyeok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.2
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    • pp.1-8
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    • 2014

  • The present study proposes a simple equation to straightforwardly determine the potential plastic hinge length in boundary element of reinforced concrete shear walls. From the idealized curvature distribution along the shear wall length, a basic formula was derived as a function of yielding moment, maximum moment, and additional moment owing to diagonal tensile crack. Yielding moment and maximum moment capacities of shear wall were calculated on the basis of compatability of strain and equilibrium equation of internal forces. The development of a diagonal tensile crack at web was examined from the shear transfer capacity of concrete specified in ACI 318-11 provision and then the additional moment was calculated using the truss mechanism along the crack proposed by Park and Paulay. The moment capacities were simplified from an extensive parametric study; as a result, the equivalent plastic hinge length of shear walls could be formulated using indices of longitudinal tensile reinforcement at the boundary element, vertical reinforcement at web, and applied axial load. The proposed equation predicted accurately the measured plastic hinge length, providing that the mean and standard deviation of ratios between predictions and experiments are 1.019 and 0.102, respectively.

  • https://doi.org/10.11112/jksmi.2014.18.2.001 인용 PDF KSCI

Performance Verification of Hinge Driving Segmented Nut Type Holding and Release Mechanism for Cube Satellite Applications (큐브위성용 힌지 구동형 분리너트식 구속분리장치의 실험적 성능검증)

  • Oh, Hyun-Ung;Lee, Myeong-Jae
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.42 no.6
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    • pp.529-534
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    • 2014

  • Pyrotechnic devices are widely used for space appendages. However, a cube satellite requirements do not permit the use of explosive pyrotechnic device. A nichrome burn wire release has typically been used for holding and release of deployable appendages of the cube satellite due to its simplicity and low cost. However, relatively low mechanical constraint force and system complexity for application of multi-deployable systems are disadvantages of the conventional mechanism. To overcome these drawbacks, we developed a hinge driving segmented nut type holding and release mechanism based on the nichrome burn wire release. The functional performance of the mechanism has been verified through release function test, static load test and shock level measurement test.

  • https://doi.org/10.5139/JKSAS.2014.42.6.529 인용 PDF KSCI

Lost Motion Analysis for Nonlinearity Identification of a 6-DOF Ultra-Precision Positioning Stage (6-자유도 초정밀 위치 결정 스테이지의 비선형성 식별을 위한 로스트 모션 해석)

  • Shin, Hyun-Pyo;Moon, Jun-Hee
    • Journal of the Korean Society for Precision Engineering
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    • v.32 no.3
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    • pp.263-268
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    • 2015

  • This paper describes lost motion analysis for a novel 6-DOF ultra-precision positioning stage. In the case of flexure hinge based precision positioning stage, lost motion is generated when the displacement of actuator is not delivered completely to the end-effector because of the elasticity of flexure hinge. Consequently, it is need to compute amount of lost motion to compensate the motion or to decide appropriate control method for precision positioning. Lost motion analysis for the vertical actuation unit is presented. The analysis results are presented in two ways: analytic and numerical analyses. It is found that they closely coincide with each other by 1% error. In finite element analysis result, the amount of lost motion is turned out to be about 3%. Although, the amount is not so large, it is necessary procedure to check the lost motion to establish the control method.

  • https://doi.org/10.7736/KSPE.2015.32.3.263 인용 PDF KSCI

Analysis of R/C frames considering cracking effect and plastic hinge formation

  • Kara, Ilker Fatih;Ashour, Ashraf F.;Dundar, Cengiz
    • Structural Engineering and Mechanics
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    • v.63 no.5
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    • pp.669-681
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    • 2017

  • The design of reinforced concrete buildings must satisfy the serviceability stiffness criteria in terms of maximum lateral deflections and inter story drift in order to prevent both structural and non-structural damages. Consideration of plastic hinge formation is also important to obtain accurate failure mechanism and ultimate strength of reinforced concrete frames. In the present study, an iterative procedure has been developed for the analysis of reinforced concrete frames with cracked elements and consideration of plastic hinge formation. The ACI and probability-based effective stiffness models are used for the effective moment of inertia of cracked members. Shear deformation effect is also considered, and the variation of shear stiffness due to cracking is evaluated by reduced shear stiffness models available in the literature. The analytical procedure has been demonstrated through the application to three reinforced concrete frame examples available in the literature. It has been shown that the iterative analytical procedure can provide accurate and efficient predictions of deflections and ultimate strength of the frames studied under lateral and vertical loads. The proposed procedure is also efficient from the viewpoint of computational time and convergence rate. The developed technique was able to accurately predict the locations and sequential development of plastic hinges in frames. The results also show that shear deformation can contribute significantly to frame deflections.

  • https://doi.org/10.12989/sem.2017.63.5.669 인용 KSCI