• Title/Summary/Keyword: structural hole

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A Study on the Development of an Elevator Rope Tension Automatic Equalizer (엘리베이터 로프장력 자동조절기 개발에 관한 연구)

  • Kim, Dong-Bok;Kim, Gab-Soon
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.5
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    • pp.60-66
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    • 2020
  • In this paper, we describe a rope tension automatic equalizer that automatically adjusts several rope tensions connecting the elevator car and the counterweight. The automatic rope tension equalizer is composed of a body, ram, and rope shaft. The body includes a cylinder hole, in which a ram is assembled. A rope shaft is assembled in a hole in the ram. Moreover, the rope is fixed to the rope shaft, with a hole through which fluid can pass between each cylinder hole and the hole of the body. The central concept is that the force of each rope is evenly distributed by the hydraulic pressure between the ram and the body cylinder when the rope is pulled. The thickness of the jaw connecting the small and large diameters of the body of the rope tension automatic equalizer was 15 mm based on structural analysis. The results of the representative experiment to install the produced rope tension equalizer on the elevator revealed it was possible to reduce the rope tension deviation by more than 71 kg.

Prediction of Error due to Eccentricity of Hole in Hole-Drilling Method Using Neural Network

  • Kim, Cheol;Yang, Won-Ho
    • Journal of Mechanical Science and Technology
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    • v.16 no.11
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    • pp.1359-1366
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    • 2002
  • The measurement of residual stresses by the hole-drilling method has been used to evaluate residual stresses in structural members. In this method, eccentricity can usually occur between the hole center and rosette gage center. In this study, we obtained the magnitude of the error due to eccentricity of a hole through the finite element analysis. To predict the magnitude of the error due to eccentricity of a hole in the biaxial residual stress field, it could be learned through the back propagation neural network. The prediction results of the error using the trained neural network showed good agreement with FE analyzed results.

Prediction for the Error of Hole Eccentricity in Hole-drilling Method Using Neural Network (신경회로망을 이용한 구멍뚫기법의 편심 오차 예측)

  • Kim, Cheol;Yang, Won-Ho;Chung, Ki-Hyun;Hyun, Cheol-Seung
    • Proceedings of the KSME Conference
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    • 2001.06a
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    • pp.956-963
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    • 2001
  • The measurement of residual stresses by the hole-drilling method has been commonly used to evaluate residual stresses in structural members. In this method, eccentricity can usually occur between the hole center and rosette gage center. In this study, the error due to the hole eccentricity is predicted using the artificial neural network. The neural network has trained training examples of stress ratio, normalized eccentricity, off-centered direction and stress error using backpropagation loaming process. The prediction results of the error using the trained neural network are good agreement with FE analyzed ones.

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Shear behavior of multi-hole perfobond connectors in steel-concrete structure

  • Xing, Wei;Lin, Xiao;Shiling, Pei
    • Structural Engineering and Mechanics
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    • v.56 no.6
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    • pp.983-1001
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    • 2015
  • This study focuses on the load carrying capacity and the force transfer mechanism of multi-hole perfobond shear connectors in steel-concrete composite structure. The behavior of multi-hole perfobond shear connector is more complicated than single-hole connector cases. 2 groups push-out tests were conducted. Based on the test results, behavior of the connection was analyzed and the failure mechanism was identified. Simplified iterative method and analytic solution were proposed based on force equilibrium for analyzing multi-hole perfobond shear connector performance. Finally, the sensitivity of design parameters of multi-hole perfobond shear connector was investigated. The results of this research showed that shear force distribution curve of multi-hole perfobond shear connector is near catenary. Shear forces distribution were determined by stiffness ratio of steel to concrete member, stiffness ratio of shear connector to steel member, and number of row. Efficiency coefficient was proposed to should be taking into account in different limit state.

Structural Behavior of Holed RC Beam mixed with Sawdust (폐톱밥 혼입 RC 유공보의 구조거동에 관한 실험적 연구)

  • Son, Ki-Sang;Lee, Jae-Hyeong
    • Journal of the Korean Society of Safety
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    • v.21 no.1 s.73
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    • pp.96-104
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    • 2006
  • This study is to find out how the sawdust-mixed RC beam with holes acts compared to two case of normal one with sawdust without hole, without sawdust. variables are ED3H1, ED3H2, ED3H1UB, ED3H2L, ED5H1, ED5H1UB, ED5H2, ED5H2L, Normal with sawdust PLA without sawdust. All sand, aggregate, cement are in accordance with KS. mixing design is also in accordance with KS and done at D remicon company in order to decrease any error in mixing manually. ED3H1 showed 7tone of maximum load capacity having only minor tensile deformation around hole, compared to the center of the beam. ED5H2L showed almost same shape of tensile strain between hole area and center of two beam length, while having 9.5 tone load capacity, incase of two holes being in the longitudinal axis. But ED5H2 in case of two holes being in same forcing direction showed 8.4tone of load capacity while having minor tensile chape around hole and normal tensile shape in the center of beam length. Two diameter 3cm hole in longitudinal axis give more effective behavior than the other case, practically. Capacity decrease between 5cm and 3cm in eccentric position form the longitudinal axis is less than percents. There is minor capacity difference between hole diameter 3cm hole, but 13tone difference of load capacity between hole diameter 5cm.

Stability Analysis of Web Plates with Openings (개구부를 갖는 Web판의 안정해석)

  • 이수곤;김순철;김명수
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.04a
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    • pp.135-140
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    • 1998
  • The buckling of the perforated web of a simply supported Η-section beam subjected to uniformly distributed load is examined by means of the finite element method. With buckling analysis results, the effect of this hole on the load carrying capacity of the beam with dimensions L/h = 11 and 13 ( L = span length h = web depth) is investigated. The parameters whose variation have been considered are hole size and location. It can be generally concluded that the buckling of the perforated web of an H-section beam is not affected seriously by the location of the perforation.

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A study on the treatment of external water pressure for the water pressure tunnel at the structural analysis of concrete lining (압력도수터널 콘크리트 라이닝 구조 계산시 외수압 처리에 관한 연구)

  • Lee, Hyeon-Sub;Lee, Young-Joon;Seo, Seung-Woo;Hwang, Young-Chul
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.17 no.6
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    • pp.653-664
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    • 2015
  • When the structural analysis is performed for the concrete lining of the water pressure tunnel, many parameters are considered such as relaxed ground loads, internal water pressure, external water pressure, the shrinkage of the concrete lining, grouting pressure, etc. But, there are no standards and manuals for the structural analysis for the concrete lining of the water pressure tunnel. Above all, the external water pressure has an much effect on the stability of tunnel. So, in case that permeability of ground is large, the external water pressure should be decreased by installation of weep hole, or reinforced ground by ground improvement grouting should be pressed by the external water pressure instead. But, when weep hole is installed to reduce the external water pressure, the many problems may me occurred. Thus, reasonable approach for treatment of the external water pressure is necessary if weep hole is not installed. Therefore, the purpose of this study is to analyze design cases and studies for treatment of the external water pressure in performing structural analysis for the concrete lining of the water pressure tunnel, and to find reasonable method for tunnel lining modeling which is the treatment of the external water pressure according to permeability of ground and consequently the design of ground improvement grouting.

The Strength Evaluation on Repaired Plain Woven CFRP Composite with a Circular Hole

  • Kwon, Oh-Heon;Park, Jun-Ho
    • International Journal of Safety
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    • v.8 no.1
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    • pp.1-5
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    • 2009
  • The CFRP composite has unique properties that offer high strength and stiffness, even though it has light weight. Therefore it can be used in many industrial applications. When mechanical fasteners are used for joining composites, high stress concentrations appear near the edge of holes prepared for accommodating structural bolts and rivets. This presence of high stress concentrations can be a source of damage. The aim of this work is to evaluate fracture behavior and patterns of plain woven CFRP with circular hole and repairing patch element. The maximum strength and pattern for the plain woven carbon composite specimen with the repaired circular hole were examined. From the results, we show that repairing of the CFRP composite specimen with ($\pi$) 3~5 mm of circular hole diameter results in load rising effect and the repairing is more effective as bigger hole specimen.

Prediction for the Error due to Role Eccentricity in Hole-drilling Method Using Backpropagation Neural Network (역전파신경망을 이용한 구멍뚫기법의 편심 오차 예측)

  • Kim, Cheol;Yang, Won-Ho;Heo, Sung-Pil;Chung, Ki-Hyun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.3
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    • pp.436-444
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    • 2002
  • The measurement of residual stresses by the hole-drilling method has been commonly used to evaluate residual stresses in structural members. In this method, eccentricity can usually occur between the hole center and rosette gage center. In this study, the error due to the hole eccentricity is predicted using the artificial neural network. The neural network has trained training examples of stress ratio, normalized eccentricity, off-centered direction and stress error using backpropagation learning process. The prediction results of the error using the trained neural network are good agreement with FE analyzed ones.

Structural Durability Analysis due to Hole Configuration Variation of Bike Disc Brake (자전거 디스크 브레이크 구멍 형상 변화에 따른 구조적 내구성 해석)

  • Han, Moonsik;Cho, Jaeung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.22 no.5
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    • pp.44-49
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    • 2014
  • As expansion and contraction of bike disk brake are happened continuously by temperature at repeated urgent braking. In this study, 3 kinds of model are designed according to configurations of holes and thermal durabilities on bike disk brake are investigated by comparing 3 models through temperature and thermal analyses. Maximum thermal stress happened at the disk contacted with pad and the connection part fixing disk rotor. Instead of initial state, the temperature is uniformly distributed at transient state. As the area of hole at disk rotor face becomes wider, thermal stress becomes lower at the initial state. On the other hand, in case the number of holes increases, thermal stress becomes lower at the elapsed time of 100 seconds. The thermal durability of bike disk brake can be improved by applying this study result with configurations of holes.