• Title/Summary/Keyword: Close Force

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A Study on Direction of the Korea Furniture Industry through the Shanghai International Furniture Fair (상해 국제 가구 박람회를 통해 본 국내가구산업의 방향성 고찰)

  • Cheon, Hye Sun
    • Journal of the Korea Furniture Society
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    • v.26 no.4
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    • pp.445-455
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    • 2015
  • Korea furniture industry is the difficulty of producing manpower supply and demand together with rising raw material and are facing severe difficulties as a diversification of consumer needs. It located so close through the International Furniture Fair in China and to identify the status of the domestic furniture industry. It also overlooks want to move forward in the direction. China International Furniture Fair was the head of the leading exchanges for furniture production worldwide. Market demand as households, yet the center is fully equipped with the chance to cooperate with the furniture production. The Shanghai International Furniture Fair was responsible for, such as providing ideas and partners for product development and production paths excavation of korea furniture manufacturers itgetda which can have a significant driving force in overcoming the recession and evaluated through this.

Theoretical and Finite Element Analysis for Structural Strength of Paperboard-stacked Structure (종이성형구조물의 구조적 강도에 대한 이론분석과 유한요소해석)

  • Park, Jong-Min;Lee, Myung-Hoon
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.5 no.1
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    • pp.13-20
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    • 1999
  • Not only is it important that the physical properties of the paperboards be appropriate for the intended end use, but the proper arrangement of the component in the built-up board is essential for attaining the optimum moment of inertia and the maximum load-carrying ability in a box. It is known to be impossible to estimate the stress distribution and deflection pattern by experiments or theoretical analysis when the corrugated fiberboard get the bending force. This study was tried theoretical and finite element analysis to analyze structural strength characteristics of corrugated fiberboards. If the linerboard and corrugating medium of every corrugated fiberboards is made from the same material, the location of neutral axis comes close to inside liner in order of DMA, DM, DMB, SW and DW, and moment of inertia of area decreases in order of DMA, DMB, DW, DM and SW. With the finite element analysis, deflection of applied loads represented SW, DM, DMA, and TW in the order of their value.

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Research on Friction Characteristics of Constant Velocity Joint Grease (등속조인트용 그리스 마찰특성 연구)

  • Lee, Sung Uk;Bae, Dae Yoon
    • Tribology and Lubricants
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    • v.29 no.4
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    • pp.223-227
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    • 2013
  • A GAF (generated axial force) is produced at a plunging-type CVJ (constant velocity joint). A high GAF can cause vibrations in a vehicle. Grease is used to reduce friction between the roller and the track of the outer case of a CVJ. The grease performance depends on the surface conditions and operating temperature. The surface of the outer case is extremely rough and hard. In recent times, the maximum operating temperature of CVJs has crossed $140^{\circ}C$, because the exhaust line is now located close to the CVJ. In this study, we examined the friction characteristics of friction additives at $25-150^{\circ}C$ and determined an optimal formulation with a low friction coefficient. This formulation can be used to develop low-friction grease that can reduce the GAF produced at a CVJ by approximately 7-26%.

Development of Prediction Model for Average Temperature in the Roughing Mill (열연 조압연공정에 있어서의 평균온도 예측모델 개발)

  • Moon C. H.;Park H. D.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2004.08a
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    • pp.368-377
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    • 2004
  • A mathematical model was developed for the prediction of the average temperature and RDT(RM Delivery temperature) in a roughing mill. The model consisted of three parts as follows (1) The intermediate numerical model calculated the deformation and heat transfer phenomena in the rolling: region by steady state FEM and the heat transfer phenomena in the interpass region by unsteady state FEM (2) The Off-line prediction model was derived from non-linear regression analysis based on the results of intermediate numerical model considering the various rolling conditions, (3) Using the heat flux in rolling region, temperature profile along thickness direction was calculated. For validation of the presented model, the rolling force per pass and RDT measued in on-line process was compared with those of model and the results showed close agreement with the existing data. In order to demonstrate the effectiveness of the proposed model, the various rolling conditions was tested.

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Deflection Analysis of Flexural Composite Members Considering Early-Age Concrete Properties (콘크리트의 초기재령특성을 고려한 합성형 휨 부재의 재령종속적 처짐해석)

  • 성원진;김정현;윤성욱;이용학
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.427-432
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    • 2003
  • An analytical method to predict the flexural behavior of composite girder is presented in which the early-age properties of concrete are specified including maturing of elastic modulus, creep and shrinkage. The time dependent constitutive relation accounting for the early-age concrete properties is derived in an incremental format by expanding the total form of stress-strain relation by the first order Taylor series with respect to the reference time. The sectional analysis calculates the axial and curvature strains based on the force and moment equilibriums. The deflection curve of the box girder approximated by the quadratic polynomial function is calculated by applying to the proper boundary conditions in the consecutive segments. Numerical applications are made for the 3-span double composite steel box girders which is a composite bridge girder filled with concrete at the bottom of the steel box in the negative moment region. The one dimensional finite element analysis results are compared with those of the three dimensional finite element analysis and the analytical method based on the sectional analysis. Close agreement is observed among the three methods.

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Behaviour of GFRP composite plate under ballistic impact: experimental and FE analyses

  • Ansari, Md. Muslim;Chakrabarti, Anupam
    • Structural Engineering and Mechanics
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    • v.60 no.5
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    • pp.829-849
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    • 2016
  • In this paper, experimental as well as numerical analysis of Glass Fiber Reinforced Polymer (GFRP) laminated composite has been presented under ballistic impact with varying projectile nose shapes (conical, ogival and spherical) and incidence velocities. The experimental impact tests on GFRP composite plate reinforced with woven glass fiber ($0^{\circ}/90^{\circ}$)s are performed by using pneumatic gun. A three dimensional finite element model is developed in AUTODYN hydro code to validate the experimental results and to study the ballistic perforation characteristic of the target with different parametric variations. The influence of projectile nose shapes, plate thickness and incidence velocity on the variation of residual velocity, ballistic limit, contact force-time histories, energy absorption, damage pattern and damage area in the composite target have been studied. The material characterization of GFRP composite is carried out as required for the progressive damage analysis of composite. The numerical results from the present FE model in terms of residual velocity, absorbed energy, damage pattern and damage area are having close agreement with the results from the experimental impact tests.

A Study on the Drag Reduction of Shear Thinning Fluid with Vertical upward Turbulent Flow (전단박화유체의 수직상향 난류유동시 저항감소에 관한 연구)

  • Cha, Kyong-Ok;Kim, Bong-gag;Kim, Jea-Geun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.22 no.12
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    • pp.1647-1656
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    • 1998
  • The drag reduction is the phenomenon that occurs only when the shear stress from the wall of pipe is beyond the critical point. The drag reduction increase as the molecular weight, concentration of the polymer and Reynolds number increase, but it is limited by Virk's maximum drag reduction asymptote. Because of the strong shear force for the polymer on the turbulent flow, the molecular weight and the drag reduction do not decrease. Such mechanical degradation of the polymer occurs in all polymer solvent systems. This paper is to identify and develop high performance polymer additives for fluid transportations with the benefits of turbulent drag reduction. In addition, drag reduction in vertical flow by measuring the pressure drop and local void fraction on vertical-up flow of close system is evaluated.

A study on the identification of dynamic characteristics of tennis racket by acoustic intensity method (음향 인텐시터법을 이용한 테니스 라켓의 동특성에 관한 연구)

  • 오재응;이유엽;염성하
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.10 no.5
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    • pp.601-610
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    • 1986
  • The acoustic intensity in the very near field of a vibrating surface reveals information about the location of sound sources and sinks. A system model of tennis racket was developed from simultaneous measurement of excitation force, surface vibration and the near field sound pressure. The characteristics of structural dynamics were obtained by standard experimental modal analysis techniques while the sound radiation characteristics were determined by estimating the acoustic intensity. In this paper, the information about vibration behviour was obtained by acoustic intensity method and some, experiments for verification were carried out. Close correlation was found between experimentally determined acoustic intensity and vibration mode patterns of the tennis racket.

The Assessment of Safe Navigation Regarding Hydrodynamic forces between Ships in Restricted Waterways

  • Lee, Chun-Ki;Lee, Sam-Goo
    • Journal of Mechanical Science and Technology
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    • v.20 no.11
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    • pp.2002-2009
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    • 2006
  • This paper is primarily focused on the safe navigation between overtaking and overtaken vessels in restricted waterways under the external forces, such as wind and current. The maneuvering simulation between two ships was conducted to find an appropriate safe speed and distance, which is required to avoid collision. From the viewpoint of marine safety, a greater transverse distance between two ships is more needed for the smaller vessel. Regardless of external forces, the smaller vessel will get a greater effect of hydrodynamic forces than the bigger one. In the case of close navigation between ships under the forces of wind and current, the vessel moving at a lower speed is potentially hazardous because the rudder force of the lower speed vessel is not sufficient for steady-state course-keeping, compared to that of the higher speed vessel.

Analysis on Plugging Force of Open-end Steel Pipe Pile (개단 강관말뚝의 관내토 폐색력 분석)

  • 최용규;김명모
    • Geotechnical Engineering
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    • v.5 no.4
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    • pp.27-36
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    • 1989
  • Load tests are executed on instrumented model piles to evaluate the magnitudes of soil plugging resistances mobilized at open-end pile tips. The plugging resistances are calculated by some existing methods, which are compared with observation. A couple of the methods are found to give good results. A new computational method to predict the plugging resistance is proposed in this paper, which also gives fairly close prodiction to the measurement, and is much simpler than the other computational methods.

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