• Title/Summary/Keyword: 점탄성소재

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A Study on the Vibration Control of the Slab Using the Viscoelastic Material (점탄성 소재를 이용한 바닥판의 진동저감에 관한 연구)

  • Kim, Soo-Jin;Hwang, Jae-Seung;Kim, Hong-Jin;Kim, Do-Hun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.526-529
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    • 2005
  • Attempts have been applied to reduce the vibration of slab. There are several method in the vibration control of slab from a traditional method such as increment of mass or stiffness of slab to a innovative method augmenting damping of slab. In this study, a attempt has been made to increase the effective damping in slab using the viscoelastic dampers made of viscoelastic material. The dampers are installed in a gab between slab and a beam. It is assumed that the stiffness of the beam is infinity for simplicity of the evaluation. we evaluate the reduction effect of the slab selected through numerical simulation and optimization process by applying it to a FEM model. The numerical simulation shows that the effective damping is increased as the number of bean is increased and the vibration control effect is very high.

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해양분야에 응용되는 고무재료

  • Gang, Seong-Rak;Na, Chang-Un
    • Rubber Technology
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    • v.9 no.2
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    • pp.89-95
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    • 2008
  • 지금까지 고무소재는 고무만이 갖는 독특한 점탄성과 동적 평형상태에서도 연구가 가능하다는 사실 때문에 일반 산업 현장에서 뿐만 아니라 군수산업에서도 매우 폭넓게 적용되고 있다. 본 리뷰에서는 해양분야, 특히 해군에서 응용되고 있는 고무 소재들에 대해서 살펴보고, 각 응용분야에 대한 기본적인 적용기술에 대해 논의하였다.

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Numerical study on impact noise control of PC slab coupled with viscoelastic material (점탄성재료가 결합된 PC슬래브의 바닥충격음 제어에 관한 수치해석 연구)

  • Hwang, Jae-Seung;Hong, Gun-Ho;Park, Hong-Geun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.1160-1166
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    • 2007
  • In this study, a new slab system that adjoint precast slabs are connected each other by viscoelastic material is proposed and numerical analysis is performed to evaluate the effect of the slab system on the vibration and noise control. Substructuring is introduced to develope the equation of motion of the slab system and the optimal properties of viscoelastic material are calculated. For the performance evaluation of the new slab system, the sound power and acceleration of the slab are compared with those of two way slab and the slab which the viscoelastic material is not connected. Numerical results show that the sound power of the new slab system can be reduced an amount of 6dB.

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Effects of Silica-Silane for CIIR Vibration Isolation Compound upon Increased Mechanical Properties (실리카-실란이 클로로부틸 방진고무 복합소재의 기계적 물성 증가에 미치는 영향)

  • Kim, Sung Min;Kim, Kwang-Jea
    • Polymer(Korea)
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    • v.39 no.1
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    • pp.107-113
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    • 2015
  • The effects of silica-silane in CIIR vibration isolation compound were investigated regarding mechanical and dynamic properties. Addition of silica-silane in the compound resulted in higher tear resistance strength and elongation at break than the control, which was increased by 13% and 14%, respectively. Other values such as tensile strength and hardness did not show significant changes. Viscoelastic property results supported that the improvement of tear resistance strength and elongation at break resulted from the formation of 3-dimensional network structure between silica and CIIR. The mechanism of the tear resistance strength and elongation at break improvement was discussed.

Investigation of Viscoelastic Properties of EPDM/PP Thermoplastic Vulcanizates for Reducing Innerbelt Weatherstrip Squeak Noise of Electric Vehicles (전기차 인너벨트 웨더스트립용 EPDM/PP Thermoplastic Vulcanizates 재료설계인자에 따른 점탄성과 글라스 마찰 소음 상관관계 연구)

  • Cho, Seunghyun;Yoon, Bumyong;Lee, Sanghyun;Hong, Kyoung Min;Lee, Sang Hyun;Suhr, Jonghwan
    • Composites Research
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    • v.34 no.3
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    • pp.192-198
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    • 2021
  • Due to enormous market growing of electric vehicles without combustion engine, reducing unwanted BSR (buzz, squeak, and rattle) noise is highly demanded for vehicle quality and performance. Particularly, innerbelt weatherstrips which not only block wind noise, rain, and dust from outside, but also reduce noise and vibration of door glass and vehicle are required to exhibit high damping properties for improved BSR performance of the vehicle. Thermoplastic elastomers (TPEs), which can be recycled and have lighter weight than thermoset elastomers, are receiving much attention for weatherstrip material, but TPEs exhibit low material damping and compression set causing frictional noise and vibration between the door glass and the weatherstrip. In this study, high damping EPDM (ethylene-propylene-diene monomer)/PP (polypropylene) thermoplastic vulcanizates (TPV) were investigated by varying EPDM/PP ratio and ENB (ethylidene norbornene) fraction in EPDM. Viscoelastic properties of TPV materials were characterized by assuming that the material damping is directly related to the viscoelasticity. The optimum material damping factor (tanδ peak 0.611) was achieved with low PP ratio (14 wt%) and high ENB fraction (8.9 wt%), which was increased by 140% compared to the reference (tanδ 0.254). The improved damping is believed due to high fraction of flexible EPDM chains and higher interfacial slippage area of EPDM particles generated by increasing ENB fraction in EPDM. The stick-slip test was conducted to characterize frictional noise and vibration of the TPV weatherstrip. With improved TPV material damping, the acceleration peak of frictional vibration decreased by about 57.9%. This finding can not only improve BSR performance of electric vehicles by designing material damping of weatherstrips but also contribute to various structural applications such as urban air mobility or aircrafts, which require lightweight and high damping properties.

FRACTAL GEOMETRY를 이용한 직물의 형태 안정성 연구

  • 이재열;강태진;정관수
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.10a
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    • pp.369-372
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    • 1998
  • 직물은 다른 소재들에 비하여 약한 외력에도 매우 쉽게 변형되고, 또한 다시 회복하는 성질을 가지고 있어서 인체에 직접 접촉하는 의복용으로 가장 적합한 유연성 소재로서 인류 역사와 함께 이용되어져왔다. 하지만 사용 중 발생하는 구김이나, 봉제 시에 발생하는 심퍼커 등은 직물이 가진 점탄성에 기인하는 현상으로서, 그 외관상의 가치를 저하시킨다. 따라서 구김이나 심퍼커를 억제하여 직물의 형태적 안정성을 획득하려는 노력들이 계속되어져 왔다. (중략)

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Berkovich 팁을 이용한 PMMA의 초미세 가공에서 가공속도가 변형거동에 미치는 영향

  • 윤성원;김현일;강충길
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.05a
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    • pp.147-147
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    • 2004
  • 폴리메틸메타크릴레이트(polymethylmethacrylate, PMMA)는 아크릴레이트계 고분자이자 열가소성 플라스틱으로써 LCD용 도광판, 콘택트렌즈, 치과용 레진, DVD 디스크용 소재, 나노임프린트용 피가공재, 나노리소그래피 공정용 레지스트 등 많은 분야에서 활발히 사용되고 있다. PMMA 와 같은 점소성 점탄성 소재의 기계적 성질 측정 및 가공을 위해서는, 응력완화 (stress relaxation), 크립 (creep)등과 같은 시간의존적 변형거동에 대한 연구가 선행되어야 한다.(중략)

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촉감 메카니즘 해석을 위한 손끝의 동적 점탄성 반응

  • 한은경;권영하
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.04a
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    • pp.280-284
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    • 1998
  • 신체 보호와 체온유지를 담당하는 피부는 인체 최대의 감각기관이다. 피부에는 온각, 냉각, 압력, 통증, 촉각, 진동 둥을 느끼는 외수용감각기들이 산재되어 있다. 그 중에서 촉감은 건축 자재, 필기구 재질, 자동차 내장재, 의류 원단과 안감 등 신체와 접촉하는 소재에 있어 제품의 질을 결정짓는 중요한 요소이다. 특히 섬유에서의 질감이란 경제적인 면과 직결되는 문제를 안고 있다.(중략)

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Numerical Study on the Control of Heavy-weight Floor Impact Noise for PC Slab Coupled with Viscoelastic Material (점탄성재료가 결합된 PC 슬래브의 중량충격음 저감에 관한 수치해석 연구)

  • Hwang, Jae-Seung;Song, Jin-Kyu;Hong, Geon-Ho;Park, Hong-Gun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.5
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    • pp.533-540
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    • 2008
  • In this study, a new slab system where a part of precast slab is connected each other by viscoelastic material is proposed and numerical analysis is performed to evaluate the effect of the connection between the material and PC slab on the vibration and noise control. Substructuring is introduced to develop the equation of motion for the slab system. In addition, the optimal properties of viscoelastic material are investigated. For the performance evaluation of the new slab system, the sound power and acceleration responses of the slab are compared with those of two way slab and one way slab, respectively. Numerical analysis results show that the sound power of the new slab system can be reduced by viscoelastic material significantly.