• Title/Summary/Keyword: 고무공

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An Experimental Study on the Physical Property of Non-Vulcanized Waterproofing Synthetic Rubber Sheet for the Underground Concrete Wall (지하 콘크리트 벽체용 미가황 합성고무시트 방수재의 물성에 관한 실험적 연구)

  • Choi, Eun Su;Lee, Dae Woo;Seo, Sang Kyo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.4
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    • pp.69-78
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    • 2012

  • This paper study on the physical property of naturally vulcanizing waterproofing synthetic rubber sheet for the underground concrete wall. In order to finding the naturally vulcanizing time, the relation of vulcanizing time and tensile strength is analysed from non-vulcanizing to naturally vulcanizing time. Physical tests such as tensile strength, tear strength: etc., under the thermal environment temperature at $-20^{\circ}C$, $-10^{\circ}C$, $20^{\circ}C$, $60^{\circ}C$. The result of experiment show that the developed rubber sheet has the delay time about 85 days and the curing time about 35 days. The tensile strength increased by about 692% and coefficient of expansion decreased by about 10% which value can be sufficiently compensate the demerit of vulcanized rubber sheet. Also, all of the physical properties of the naturally rubber sheet satisfy the KS standard and compare to the vulcanized rubber sheet, the developed naturally rubber sheet have excellent durability.

  • https://doi.org/10.11112/jksmi.2012.16.4.069 인용 PDF KSCI

Study of Thermal Decomposition of Kevlar/EPDM (Kevlar/EPDM 고무계 내열재의 열반응 연구)

  • Kim, Yun-Chul;Jung, Sang-Ki;Kang, Yoon-Goo;Lee, Seung-Goo
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.11a
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    • pp.257-260
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    • 2010

  • The purpose of this paper is to introduce a method to predict the case thermal insulation charred and erosion thickness as a function of the exposure time to combustion gases and in solid rocket motors. The sizing of the insulator requires a good estimation of the thermal and mechanical loads at the wall. The method is particularly suitable for internal insulation areas subjected to high radiative, convective heat fluxes and $Al_2O_3$ slag pool. The mathematical approach and lab-scale experiment were intentionally simplified in order to obtain some simple and rapid relationships particularly useful for trade-off studies and thermal insulation preliminary design. The method was utilized to compute the charred and erosion thicknesses of the insulation on the aft chamber domes. A comparison between theoretical and experimental insulator char thicknesses of the motor insulation is reported, indicating the applicability of the predictive method employed.

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해상풍속측정용 마스트의 충격해석에 관한 연구

  • Lee, Gang-Su;Kim, Man-Eung;Son, Chung-Ryeol
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2009.04a
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    • pp.108-108
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    • 2009

  • The main object of this research is to minimize the shock effects which frequently result in fatal damage in wind met mast on impact of barge. The collision between wind met mast and barge is generally a complex problem and it is often not practical to perform rigorous finite element analyses to include all effects and sequences during the collision. LS-dyna generally purpose explicit finite element code, which is a product of ANSYS software, is used to model and analyze the non-linear response of the met mast due to barge collision. A significant part of the collision energy is dissipated as strain energy and except for global deformation modes, the contribution from elastic straining can normally be neglected. On applying impact force of a barge to wind met mast, the maximum acceleration, internal energy and plastic strain were calculated for each load cases using the finite element method and then compare it, varying to the velocity of barge, with one varying to the thickness of rubber fender conditions. Hence, we restrict the present research mainly to the wind met mast and also parametric study has been carried out with various velocities of barge, thickness of wind met mast, thickness and Mooney-Rivlin coefficient of rubber fender with experimental data. The equation of motion of the wind met mast is derived under the assumption that it was ignored vertical movement effect of barge on sea water. Such an analyzing method which was developed so far, make it possible to determine the proper size and material properties of rubber fender and the optimal moving conditions of barge, and finally, application method can be suggested in designing process of rubber fender considering barge impact.

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