• Title, Summary, Keyword: 에너지감쇄

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Basic Study of the Hysteresis of a Nano Shock Absorbing Damper by Employing Mixed Lyophobic Coating Silica Gel (실리카 겔의 소수화 코팅 혼합 정도에 따른 나노 충격 흡수 장치의 이력 현상에 대한 기초적 연구)

  • 문병영;김흥섭
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.2
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    • pp.59-66
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    • 2003
  • A novel application of nano-technology in the field of engineering, called colloidal damper, is investigated. This device is complementary to the hydraulic damper, having a cylinder-piston construction. Particularly for colloidal damper, the hydraulic oil is replacedby a colloidal suspension, which is consisted from a nano-porous matrix with controlled architecture and a lyophobic fluid. In this experimental work, the porous matrix is composed from silica gel, with labyrinth architecture, coated by organo-silicones substances in order to achieve a hydrophobic surface. Water is considered as associated lyophobic fluid. The colloidal damper test rig and the measuring technique of the hysteresis are described. the influence of the hydrophobicity level upon the colloidal damper hysteresis is investigated, for silica gels with similar pores distribution. A certain desired shape of the hysteresis can be achieved by employing mixture of silica gels with different level of hydrophobicity and/or architecture. With these results, it is believed that the proposed damper can be designed and be applied to the desired structure.

Effect of Water Volume and Relaxation Time in the Design of Nano Shock Absorbing Damper Using Silica Particle (실리카 분말을 이용한 나노 충격완화 장치의 설계에서 작동 유체 영향과 복원 시간에 대한 연구)

  • 문병영;김병수
    • Journal of the Korean Ceramic Society
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    • v.40 no.3
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    • pp.286-292
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    • 2003
  • In this study, new shock absorbing system was proposed using silica gel particles according to the nano-technology. For the design and real application of the proposed damper, an experimental investigations are carried out using colloidal damper, which is statically loaded. The porous matrix is composed from silica gel(labyrinth architecture), coated by organo-silicones substances, in order to achieve a hydrophobic surface. Water is considered as associated lyophobic liquid. Reversible colloidal damper static test rig and the measuring technique of the static hysteresis were described. Iufluence of the water volume and particle diameters upon the reversible colloidal damper hysteresis was investigated. Also, influence of the relaxation time on the hysteresis of the damper was investigated. As a result, the proposed new shock absorbing damper is proved as an effective one, which can be replaced for the conventional hydraulic damper.

Investigation on Damping of Steel Fiber Reinforced Concrete (강섬유철근콘크리트보의 에너지감쇠에 관한 연구)

  • 강보순
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • pp.159-169
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    • 2000
  • 본논문에서는 강섬유 철근 콘크리트 보(SFRC) 의 감쇄 거동에 대해서 실험적인 방법과 수치 해석적인 방법으로 연구를 수행하였다 SFRC는 보다 향상된 에너지 소산능력으로 일반 철근 콘크리트보에 비하여 뛰어난 감쇄 거동을 보인다. 감쇄거동은 종방향 철근비강섬유의 형태와 부피 콘크리트 강도 응력 수준등에 의해 영향을 받는다 SFRC보의 감쇠는 다양한 수준의 균열상태에서의 동적실험 데이터를 통하여 평가하였다 곡률과 감쇠의 관계식에 기초한 유한요소 프로그램(TICAL) 이 개발되었으며 0.44%의 강섬유를 혼입한 보의 경우 5-35%의 감쇠비 증가를 보였다

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Review of the Transfer Function and Coupling Configuration for Microwave Filter (마이크로파 필터의 전달 함수 및 결합 구조 고찰)

  • Uhm, M.S.;Lee, J.S.;Yom, I.B.;Lee, S.P.
    • Electronics and Telecommunications Trends
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    • v.18 no.2
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    • pp.67-78
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    • 2003
  • 모든 RF 통신 시스템에서 사용되는 마이크로파 필터는 통과 대역에서 에너지를 전달하고, 저지 대역에서 에너지를 감쇄시키는 역할을 한다. 주파수 사용 효율을 높이기 위해서 대역내 평탄도 및 군지연 특성이 우수하고, 대역외에서 높은 감쇄를 갖는 필터 개발에 많은 연구가 이루어졌다. 본 고에서 필터 개발에 필수적인 전달 함수 특성 및 결합 구조에 관하여 고찰한다.

Damping of RC and SFRC Beams (철근콘크리트 및 강섬유 철근콘크리트보의 에너지감쇄)

  • Kang Bo-Soon
    • Journal of the Korean Society for Railway
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    • v.8 no.2
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    • pp.122-127
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    • 2005
  • In this paper, damping behavior of steel fiber reinforced concrete(SFRC) beams by experimental and numerical method is discussed. Because of its improved ability to dissipate energy, SFRC has a better damping behavior than that of reinforced concrete(RC). Damping behavior is influenced by longitudinal reinforcement ratio, volume md type of steel fiber, strength of concrete and the stress level. Damping in the SFRC beams has been evaluated from dynamic experimental test data at various levels of cracked states in the beams. A FEM program(TICAL) has been developed based on the relationships between curvature and damping. It is observed far SFRC beams with 0.44$\%$ of tensile reinforcement steel that approximate 5$\%$ to 35$\%$ was relatively increased in the damping ratio generally depending on the load level.

Nano-particle size detection by LII decay method (LII 감쇄법을 이용한 나노입자 크기측정)

  • 엄규섭;박성종;박철웅;한재원;최원호;정광화;신용현
    • Proceedings of the Optical Society of Korea Conference
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    • pp.60-61
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    • 2002
  • Laser-induced incandescence (LII) 측정법은 조사된 레이저에 의하여 입자가 가열됨에 따라서, 그 온도에 상응하는 흑체복사의 시간적 감소추이가 입자의 크기에 따라서 달리 나타나는 것을 이용하여 입자의 크기를 측정하는 방법이다. LII 감쇄법은 레이저에 의하여 가열된 입자의 에너지 균형 상관식에서 입자의 크기가 클수록 신호의 감쇄속도가 느리고, LII 신호의 감쇄비가 실험적으로 입자의 크기에 비례한다는 사실을 이용하여 연소진단에 응용되어 왔다. (중략)

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Wave Reflection and Transmission Characteristics of Flap-type Floating Breakwaters (플랩형 부유 방파제의 파랑 반사 및 전달 특성)

  • Jeong, Shin-Taek;Park, Woo-Sun;Kim, Jeong-Dae
    • Proceedings of the Korea Water Resources Association Conference
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    • pp.2141-2145
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    • 2008
  • Three kind of system composed with buoyant flap hinged at the sea floor are modeled experimentally. The mechanically coupled system provides shelter by reflecting incident waves and by attenuating wave energy through structural and viscous damping. The characteristics of wave reflection, transmission and dynamic angle of the flap oscillation for various conditions were investigated. The structure can minimize wave transmission by attaching offshore wing wall.

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Development of Frictional Wall Damper and Its Analytical Applications in R/C frame Structures (벽식마찰감쇄기의 개발 및 R/C 골조구조물에의 해석적 적용)

  • 조창근;박문호;권민호;강구수;서상길
    • Journal of the Korea Concrete Institute
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    • v.14 no.5
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    • pp.718-725
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    • 2002
  • A wall type friction damper is newly Proposed in this paper to improve the performance of R/C framed structures under earthquake loads. Although traditional dampers are usually placed as bracing members, the application ot bracing-type dampers into R/C structures is not as simple as those of steel structures due to the connection between R/C members and dampers and the stress concentration in connection region. Proposed damper is consisted of Teflon-sheet slider and R/C shear wall. The damper can also avoid stress concentration and reduce P-Δ effect. To evaluate the performance of proposed damper, nonlinear dynamic analyses are carried on 10 story and 3 bay R/C structures with numerical model for the damper. It is shown that the damper reduces the inter-story drifts and the time-historic responses; especially the damper prevents from forming plastic hinges on the lower columns.

An effect of length between the EUT and surge generator in surge immunity test (EUT와 서지 발생기 사이의 거리가 서지 내성 시험에 미치는 영향)

  • 이주광;임순재
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.6 no.4
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    • pp.57-61
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    • 1995
  • This paper reports on a theoretical and experimental study on an effect of length between the EUT and surge generator. In the case of using 40m line, surge energy was decreased to 77% of the output of surge generator.

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Design of RF Energy Detector for Spectrum Sensing in TV White Space Transceiver (TV White Space 송수신기의 스펙트럼 센싱을 위한 RF 에너지 검출 회로 설계)

  • Kim, Jong-Sik;Shin, Hyun-Chol
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.11 no.2
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    • pp.83-91
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    • 2012
  • An RF energy detector for spectrum sensing in TV white space transceiver is presented. It is based on an RF active filtering technique that comprises a low-noise amplifier with a frequency-translation high-pass filtering feedfoward loop, which attenuates the unwanted sideband energy and only passes the wanted band energy. Unlike the conventional architecture, a new architecture that can attenuate both sidebands at the same time is proposed. A simplified system modeling method is presented to assess the non-ideality effects on the RF energy detector performances. System behavioral simulations demonstrate that the proposed architecture can be instrumental for realizaing a RF energy detector circuit in CMOS.