• Title/Summary/Keyword: Slip Form

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Comparison of Concrete Setting Properties for the Application of Tapered Slip-Form method (변단면 슬립폼 공법 적용을 위한 콘크리트의 응결 특성 비교)

  • Song, Yong-Soon;Yang, Woo-Yong;Jung, Gil-Su;Seo, Young-Hwa
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.459-460
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    • 2010
  • For the application of slip form method to the pylon of Yi Sun-shin bridge which has much variation in its cross section, the change of setting properties of concrete due to changing weather and long pumping distance has to be taken into consideration. Different setting properties of several types of cement according to the amount of compound and ambient temperature were observed in this paper.

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DUFOUR AND HEAT SOURCE EFFECTS ON RADIATIVE MHD SLIP FLOW OF A VISCOUS FLUID IN A PARALLEL POROUS PLATE CHANNEL IN PRESENCE OF CHEMICAL REACTION

  • VENKATESWARLU, M.;BABU, R. VASU;SHAW, S.K. MOHIDDIN
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.21 no.4
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    • pp.245-275
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    • 2017
  • The present investigation deals, Dufour and heat source effects on radiative MHD slip flow of a viscous fluid in a parallel porous plate channel in presence of chemical reaction. The non-linear coupled partial differential equations are solved by using two term perturbation technique subject to physically appropriate boundary conditions. The numerical values of the fluid velocity, temperature and concentration are displayed graphically whereas those of shear stress, rate of heat transfer and rate of mass transfer at the plate are presented in tabular form for various values of pertinent flow parameters. By increasing the slip parameter at the cold wall the velocity increases whereas the effect is totally reversed in the case of shear stress at the cold wall. It is observed that the effect of Dufour and heat source parameters decreases the velocity and temperature profiles.

A Study on The Material Selection and Characteristic Investigation of Rotor Bar and End Ring of Induction Motor for High Speed Train (고속전철용 견인전동기의 회전자 바와 엔드링의 재질선정 및 특성고찰에 관한 연구)

  • 이상우;김근웅;윤종학;이기호;한성수
    • Proceedings of the KSR Conference
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    • 1998.11a
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    • pp.187-193
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    • 1998
  • An inverter-driven induction motor is used as the traction motor for a high speed drive system that required safty, reliability and performance and so on. rotor bar and end ring of the traction motor are the electrical equipments which form the conductive close loop and then induce current by interaction wi th the current of stator. the materials selection of rotor bar and end ring are seriously considered in the aspects of electrical and mechanical specification and Motor slip relation to inverter. Particularly motor slip guarantee the safty and reliability of induction motor. this paper show the material selection and the determining of slip in the design of traction motor for high speed train by analyzing the specifications of material being used currently.

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Strength prediction of steady laminar fluid with normal velocity distribution: A simplified truncation technique

  • Mohamed A. Khadimallah;Muzamal Hussain;Elimam Ali;Abdelouahed Tounsi
    • Advances in concrete construction
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    • v.15 no.5
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    • pp.313-319
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    • 2023
  • In this paper, the analytic solution has been found by using truncation approach. With the help of suitable substitution, different physical parameters are yielded in their non-dimensional form. The governing boundary layer partial differential equations are reduced to a set of ordinary ones by using appropriate similarity transformations. The velocity profile across the domain have also been taken into account. The effect normal velocity profiles buoyancy parameter, slip parameter, shrinking parameter, Casson fluid parameter on the heat profile. It is found that the normal velocity profiles rise with the buoyancy parameter and for the slip parameter. It is observed that the normal velocity profile decreases with the increase of shrinking parameter. The reverse behiour is found for the Casson fluid parameter. The results are numerically computed, analyzed and discussed. For the efficiency of present model, the results are compared with earlier investigations.

Finite Element Stress Analysis of Implant Prosthesis According to Friction Fit or Slip Fit of Internal Connection System between Implant and Abutment (임플랜트와 지대주 간 내측연결 시스템에서 Friction Fit와 Slip Fit에 따른 유한요소 응력분석)

  • Jang, Doo-Ik;Jeong, Seung-Mi;Chung, Chae-Heon
    • Journal of Dental Rehabilitation and Applied Science
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    • v.21 no.2
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    • pp.113-132
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    • 2005
  • The purpose of this study was to assess the stress-induced pattern at the supporting bone, the implant fixture, the abutment and the abutment screw according to a friction-fit joint (Astra; Model 1) or slip- fit joint (Frialit-2; Model 2) in the internal connection system under vertical and inclined loading using finite element analysis. In conclusion, in the internal connection system of the implant and the abutment connection methods, the stress-induced pattern at the supporting bone, the implant fixture, the abutment and the abutment screw according to the abutment connection form had difference among them, and the stress distribution pattern usually had a widely distributed tendency along the inner surface of the implant fixture contacting the abutment post. The magnitude of the stress distributed in the supporting bone, the implant fixture, the abutment and the abutment screw was higher in the friction-fit joint than in the slip-fit joint. But it is considered that the further study is necessary about how this difference in the magnitude of the stress have an effect on the practical clinic.

Control Method of Mobile Robots for Avoiding Slip and Turnover on Sloped Terrain Using a Gyro/Vision Sensor Module (Gyro/Vision Sensor Module을 이용한 주행 로봇의 미끄러짐 및 넘어짐 회피 제어 기법)

  • Lee Jeong-Hee;Park Jae-Byung;Lee Beom-Hee
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.8
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    • pp.669-677
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    • 2005
  • This acticle describes the control method of mobile robots for avoiding slip and turnover on sloped terrain. An inexpensive gyro/vision sensor module is suggested for obtaining the information of terrain at present and future. Using the terrain information and the robot state, the maximum limit velocity of the forward velocity of the robot is defined fur avoiding slip and turnover of the robot. Simultaneously the maximum value of the robot velocity is reflected to an operator in the form of reflective force on a forte feedback joystick. Consequently the operator can recognize the maximum velocity of the robot determined by the terrain information and the robot state. In this point of view, the inconsistency of the robot movement and the user's command caused by the limit velocity of the robot can be compensated by the reflective force. The experimenal results show the effectiveness of the suggested method.

A Study on the Air Foil Journal Bearing Analysis with Perturbed Rarefaction Coefficients

  • Lee, Yong-Bok;Park, Dong-Jin;Kim, Chang-Ho;Jang, Gun-Hee
    • KSTLE International Journal
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    • v.7 no.2
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    • pp.27-34
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    • 2006
  • Knudsen number is the ratio of molecular mean free path versus mm thickness and the criterion to determine the flow form. When its value is lower than 0.01, the flow can be assumed to has no slip boundary condition. And in the case that the value is between 0.01 and 10, then the flow has slip boundary condition at both the adjacent walls. The condition of the air flow between the rotating journal and top foil in the air foil bearing is determined by the rotating speed and load, and the Knudsen number is also varied by those values. Because the molecular mean free path is variable to the pressure and temperature, more exact formulation is necessary to understand and analyze the flow regime. In this study, the analysis considering Knudsen number formulated with those variables (pressure, temperature and mm thickness) was executed. The approximate value was examined using the equation to confirm whether the flow has the slip or no-slip boundary condition. From the analytic investigation, it was decided to range approximately 0.01 to 1.0 and the flow can be supposed to have the slip boundary condition. Under the condition of the slip flow, the static characteristics of the air foil bearing were examined using modified Reynolds equations. The results were compared with those considering no slip condition. It shows that the slip condition makes the flow decelerates and the load carrying capacity decreases compared with no slip condition. And as the bearing number and eccentricity ratio increase, the load carrying capacity also increased at both the cases. From this result, it can be supposed that the bearing torque also increases. In the analysis of the dynamic characteristics, the perturbed Knudsen number was taken into consideration. Because the Knudsen number is expressed as the terms of each variable, the perturbed equation can be simply derived. The results of both cases considering and not considering Knudsen number were compared each other. In the case of the direct terms of the stiffness and damping coefficients, the difference between both cases was little and increased as the bearing number and eccentricity ratio increased. And the cross terms have less or more differences.

A low damage and ductile rocking timber wall with passive energy dissipation devices

  • Loo, Wei Yuen;Quenneville, Pierre;Chouw, Nawawi
    • Earthquakes and Structures
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    • v.9 no.1
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    • pp.127-143
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    • 2015
  • In conventional seismic design, structures are assumed to be fixed at the base. To reduce the impact of earthquake loading, while at the same time providing an economically feasible structure, minor damage is tolerated in the form of controlled plastic hinging at predefined locations in the structure. Uplift is traditionally not permitted because of concerns that it would lead to collapse. However, observations of damage to structures that have been through major earthquakes reveal that partial and temporary uplift of structures can be beneficial in many cases. Allowing a structure to move as a rigid body is in fact one way to limit activated seismic forces that could lead to severe inelastic deformations. To further reduce the induced seismic energy, slip-friction connectors could be installed to act both as hold-downs resisting overturning and as contributors to structural damping. This paper reviews recent research on the concept, with a focus on timber shear walls. A novel approach used to achieve the desired sliding threshold in the slip-friction connectors is described. The wall uplifts when this threshold is reached, thereby imparting ductility to the structure. To resist base shear an innovative shear key was developed. Recent research confirms that the proposed system of timber wall, shear key, and slip-friction connectors, are feasible as a ductile and low-damage structural solution. Additional numerical studies explore the interaction between vertical load and slip-friction connector strength, and how this influences both the energy dissipation and self-centring capabilities of the rocking structure.