• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.634-639
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• 2004

Under light collision accidents, the energy absorption strategy for the coupler and expansion tube of the TTX(Tilting Train Express) initial design is established in the paper. Also, 1st shearing bolts are designed. When the absorbed energy of the coupler reaches its maximum, the connecting bolts between the coupler and the car body are sheared off not to transmit the impact force to the car body structure. To absorb more energy after the lst shearing bolts work, a expansion tube is designed conceptually and installed at the rear part of the coupler. Using Hyper-Mesh and LS-DYNA, pre/post processing and light collision analyses are preformed, respectively.

• Design & Manufacturing
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• 제15권1호
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• pp.41-47
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• 2021

The Fine Blanking process is an effective precision shearing process that can obtain a smooth cutting surface and high product precision through a single blanking process. It is widely used in various manufacturing fields. However, shearing through this fine blanking process is only intended to minimize burrs, die rolls and fracture surfaces and does not completely remove them. Therefore, it is necessary to study the minimization of burrs, die rolls and fracture surfaces in the fine blanking process. In this study, a study was conducted on the relationship between the fracture surface and process conditions that occurred during product production using the fine blanking process. For this purpose, the shape of the V-ring indenter, the distance to the punch, and the pressure force, clearance, shear rate, and physical properties of the material were selected as process and design variables, and the relationship with the fracture surface according to each process and design condition was tested. It was analyzed through the Experimental Design Method.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.112-115
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• 2004

Bond between reinforcing bar and surrounding concrete is supposed to transfer load safely in the process of design of reinforced concrete structures. Bond failure of reinforcing bar generally take place by splitting of the concrete cover as bond force between concrete and reinforcing bars exceeds the confinement of the concrete cover and reinforcement. However, the confinement force has a limitation. Thus, the only variable is the bearing angle corresponding to the change of bond force. Higher rib height bars possessing higher shearing resistance can maintain higher bearing angle and higher splitting resistance when bars are highly confined, and consequently higher bond strength, than lower rib higher bars. In this study, from the evaluate bond strength of high Relative Rib Area Bars Using beam-end test specimens are compared with the current provisions for development of reinforcement, and the improved design method of bond strength is proposed.

• Journal of Advanced Marine Engineering and Technology
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• 제2권1호
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• pp.3-14
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• 1978

The authors have developed a calculating method of propeller shaft alignment by the finite element method. The propeller shaft is divided into finite elements which can be treated as uniform section bars. For each element, the nodal point equation is derived from the stiffness matrix, the external force vector and the section force vector. Then the overall nodal point equation is derived from the element nodal point equation. The deflection, offset, bending moment and shearing force of each nodal point are calculated from the overall nodal point equation by the digital computer. Reactions and deflections of supporting points of straight shaft are calculated and also the reaction influence number is derived. With the reaction influence number the optimum alignment condition that satisfies all conditions is calculated by the simplex method of linear programming. All results of calculation are compared with those of Det norske Veritas, which has developed a computor program based on the three-moment theorem of the strength of materials. The authors finite element method has shown good results and will be used effectively to design the propeller shaft alignment.

• 상하수도학회지
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• 제19권2호
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• pp.214-220
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• 2005

Errors may occur due to analysis methods and water quality during the application of the on-line particle counter In water treatment process. Errors caused by analysis methods include particle destruction by shear force due to inflow speed and tube friction, as well as interruption by screening, bubbles and contaminants. Since errors happen frequently because of these factors, it is necessary to examine and evaluate such errors during the application of a particle counter. Errors can be large due to screening and bubbles. Measurement values are effective for water analysis after filtration process. However, because of screening, only measurement values for particles above $7{\mu}m$ are valid for water with a turbidity between 3-10NTU. As particle numbers around $10{\mu}m$ increase a lot after ozone treatment, sufficient pretreatment process is necessary. Physical conditions should keep stable for inflow to decrease errors caused by shear force.

• 소성∙가공
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• 제30권3호
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• pp.149-156
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• 2021

Fine blanking is a high-precision process combining principles of metal stamping and cold forming. Unlike conventional metal stamping, fine blanking uses a special triple action such as V-ring force, counter force, shearing force. This study performed the effect of pocket-shaped compression molding on the mold life of the fine blanking using the 7.4mm thick SM45C material. In order to determine the lifespan of the punch and die in the fine blanking molds, a trial mold was manufactured and various punch materials were selected to perform the mold life test. A study on the life of a fine blanking mold by applying a thick plate material was experimentally performed through a mold test.

• 해양환경안전학회지
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• 제18권6호
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• pp.584-590
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• 2012

본 연구에서는 고정자와 회전자에 의해 발생하는 전단력(Shearing force)을 이용한 선박용 연료유 균질기(Homogenizer) 개발에 관한 연구를 수행하였다. 균질기의 균질화 및 미립화 정도에 대한 성능을 조사하기 위하여 IFO 380 cSt Bunker-C 시료에 전처리(Pre-treatment)를 시행하였다. 전처리한 시료의 슬러지(Sludge) 저감 효과를 확인하기 위하여 유청정기(Oil purifier)를 이용하였다. 실험결과 균질기로 전처리한 시료에서 슬러지양이 약 13 % 감소하는 것을 확인하였다. 또한, 전처리 후 유청정한 시료를 실제 보일러 시스템에서 연소시켜 CO가 감소하는 연소특성 경향을 확인하였다. 이와 같은 결과를 통해 개발된 선박용 연료유 균질기를 실선에 적용할 경우 연료비 및 운항비용 절감 효과가 있을 것으로 판단된다.

• 대한토목학회논문집
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• 제33권4호
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• pp.1261-1270
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• 2013

현행 국내 1등교 활하중 설계기준은 DB-24하중과 DL-24하중을 적용하고 있다. 특히 45m 이상의 장경간 교량에서는 DB-24하중보다 DL-24 하중에 의한 전단력, 모멘트가 지배적인 것으로 나타나 대부분 DL-24하중을 적용하여 설계하고 있다. 그러나 실제 교량에서트럭하중은 한 점에 머무르며 작용하지 않고 교량 위를 종방향으로 이동하며 작용하므로, 이러한 이동 효과를 고려하여 이동트럭하중(ML-24)을 정의하여 DL-24하중과 비교한 결과, DL-24하중은 50m 경간을 기준으로 이동트럭 하중(ML-24)에 의한 전단력을 전 구간에서 만족시키지 못하였고, 모멘트의 경우도 일부구간에서 만족하지 못하는 것으로 나타났다. 이에 본 논문에서는 경간 50m를 기준으로 현재 DL-24하중을 구성하는 하중 인자를 조정하여 새로운 활하중 모델인 RL-24하중을 제시하였으며, 이를 경간 45~60m 단순교에 적용시켜 검토한 결과, 실제 작용 하중과 유사한 ML-24하중에 의해 교량에 작용하는 모멘트와 전단력을 모두 만족하였으며, 특히 문제점으로 발견되었던 부재 중앙과 부재 단부에서의 전단력 비율이 일정하게 유지되는 결과를 얻었다. 또한 국내의 활하중 모델들과의 비교를 통하여 RL-24하중 조정안의 적절성과 그 적용성을 검토하였다. 본 연구에서는 최근 연구개발과 실용화가 활발한 60m 경간급의 1등급 교량에 대하여 실제 트럭의 이동 효과를 고려하여 모멘트와 전단력에 대하여 합리적인 설계가 이루어질 수 있도록 새로운 설계기준을 제시하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1993년도 가을 학술발표회 논문집
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• pp.261-266
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• 1993

This study was performed to evaluate the flexural behavior of polymer concrete sandwich panels which was made of unsaturated polymer resin. Bending tests under 4point loading was conducted for the 8 type of sandwich panel with different core and facing thickness. Results show that Load-Deflection, shearing force- shear strain, moment strength - strain relationships were effected by core and facing thickness.

• 한국정밀공학회지
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• 제25권6호
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• pp.159-167
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• 2008

Cooling lubricants are used in machining operations in order to reduce friction at the tool-chip and tool-workpiece interfaces, cool both chip and tool, and remove chip. Furthermore, they influence a strong effect on the shearing mechanisms and, consequently, on the machined surface quality and tool wear. However, several researchers state that the costs related to cutting fluids is frequently higher than those related to cutting tools. Moreover, the cooling lubricants cause an increase in both worker's health and social problems related to their use and correct disposal. Therefore, many researchers have focused on the environmentally conscious machining technologies. One of the technologies is known as MQL(Minimum Quantity Lubrication) machining. In this paper, an experimental model to obtain the optimal cutting conditions in MQL turning was suggested, and the effects of cutting conditions on surface roughness and cutting force were analyzed. For these purposes, FFD (Fractional Factorial Design) and RSM (Response Surface Methods) were used for the experiment. Cutting force and surface roughness with different cutting conditions were measured through the external cylindrical turning of Al 6061 based on the experiment plan. The measured data were analyzed by regression analysis and verification experiments with random conditions were conducted to confirm the suggested experimental model.