• 제목/요약/키워드: viscous

검색결과 2,151건 처리시간 0.024초

보통중심가새골조의 내진보강을 위한 자가복원형 점성감쇠기 시스템 개발 (Development of Self-centering Viscous Damper System for Seismic Retrofit of Ordinary Concentrically Braced Frame)

  • 김도연;최혁순;강주형;이용선
    • 한국구조물진단유지관리공학회 논문집
    • /
    • 제27권6호
    • /
    • pp.70-78
    • /
    • 2023
  • 보통중심가새골조는 단순한 설계절차를 갖는 이점이 있다. 이와 같은 이유로, 지진하중에 대한 내진성능이 다른 골조 시스템에 비해 크게 효과적이지 않음에도 불구하고 중간 또는 낮은 수준의 지진을 받는 소규모 골조 구조물에 널리 사용되어 왔다. 횡방향 지진 하에서 압축 거동에 대해 취약한 가새부재를 갖는 보통중심가새골조의 내진성능을 향상시키기 위해, 통상적으로 점성감쇠기에 의한 내진보강이 도입되어 왔다. 하지만, 점성감쇠기 자체는 일반적으로 구조물을 원래 위치로 복원시킬 수 있는 강성을 갖지 않는다. 이는 구조물에 잔류 변위를 유발시킬 수도 있다. 이 논문에서는 휨강성을 갖는 상·하부 보가 비선형-탄성 스프링 역할을 하여 외부 변위 이력을 받는 스프링-감쇠기 시스템을 원래 위치로 복원시키는 자가복원형 점성감쇠기 시스템이 개발되었다. 단순화된 골조 구조물에 대한 수치해석은 개발된 자가복원형 점성감쇠기 시스템을 포함할 경우 지진이 가해지는 동안 에너지 소산을 통해 어떻게 골조 구조물의 향상된 내진성능을 가져오는지 보여준다.

Mechanical analysis of non-uniform beams resting on nonlinear elastic foundation by the differential quadrature method

  • Hsu, Ming-Hung
    • Structural Engineering and Mechanics
    • /
    • 제22권3호
    • /
    • pp.279-292
    • /
    • 2006
  • A new approach using the differential quadrature method (DQM) is derived for analysis of non-uniform beams resting on nonlinear media in this study. The influence of velocity dependent viscous damping and strain rate dependent viscous damping is investigated. The results solved using the DQM have excellent agreement with the results solved using the FEM. Numerical results indicated that the DQM is valid and efficient for non-uniform beams resting on non-linear media.

비정렬 혼합격자 기반 유동해석 기법 소개 (INTRODUCTION TO UNSTRUCTURED HYBRID MESH BASED FLOW SIMULATION TECHNIQUE)

  • 안형택
    • 한국전산유체공학회:학술대회논문집
    • /
    • 한국전산유체공학회 2009년 춘계학술대회논문집
    • /
    • pp.112-115
    • /
    • 2009
  • In this paper, flow simulation algorithms for utilizing unstructured hybrid meshes are introduced. First, various types of meshes are introduced. Advantages and disadvantages of each type of meshes are discussed. Unstructured hybrid mesh approach, that is best suited for high speed viscous flow simulation, is presented. Lastly, various types of flow simulations using unstructured hybrid meshes are introduced.

  • PDF

다단 축류형 터빈의 유동 특성 해석 (Flow Characteristics in a Multistage Axial Turbine)

  • 엄인식;박준영;백제현
    • 한국전산유체공학회:학술대회논문집
    • /
    • 한국전산유체공학회 2000년도 추계 학술대회논문집
    • /
    • pp.149-154
    • /
    • 2000
  • The flows through a turbomachinery tend to be extremely complex due to its inherent unsteady and viscous phenomena. A good analysis of the flows associated with rotor/stator interactions in turbomachinery will be great help in design stage. In this investigation, unsteady viscous flow structurts through one and half stage of UTRC large scale rotating axial turbine are analysed. The numerical data was compared with experimental data and showed good agreement.

  • PDF

Slit 近傍의 Stokeslet 에 의한 2次元의 느린 粘性流動 (Two-Dimensional Slow Viscous Flow Due to a Stokeslet Near a Slit)

  • 고형종;김문언
    • 대한기계학회논문집
    • /
    • 제7권4호
    • /
    • pp.386-391
    • /
    • 1983
  • Two-dimensional slow viscous flow due to a stokeslet near a slit is investigated on the basis of Stokes approximation. Velocity fields and stream function are obtained in closed forms by finding two sectionally holomorphic functions which are determined by reducing the problem to Riemann-Hilbert problems. The force exerted on a small cylinder is calculated for the arbitrary position of the cylinder translating in an arbitrary direction. The features of fluid flow are also investigated.

전자기 액튜에이터를 이용한 1/4차량 모델의 능동 진동 제어에 관한 연구 (Active Vibration Control of 1/4 Vehicle Model using Electro-magnetic Actuator)

  • 허신;최강윤;김유일
    • 연구논문집
    • /
    • 통권23호
    • /
    • pp.81-92
    • /
    • 1993
  • In this study, quarter vehicle model is used to analyse vibration control effects for ride comfort and handling safety according to this three kinds of control methods, which are the modal control, the sky-hook control and the linear viscous damping control. We performed theoretical analysis and experiments and compared two results. In experiments, electro-magnetic actuator was employed as a force actuator. It is shown that all three methods can effectively control the vehicle model. The modal control method gives similar control results using gain less than the viscous damping control.

  • PDF

A STABILITY RESULT FOR THE COMPRESSIBLE STOKES EQUATIONS USING DISCONTINUOUS PRESSURE

  • Kweon, Jae-Ryong
    • 대한수학회지
    • /
    • 제36권1호
    • /
    • pp.159-171
    • /
    • 1999
  • We formulate and study a finite element method for a linearized steady state, compressible, viscous Navier-Stokes equations in 2D, based on the discontinuous Galerkin method. Dislike the standard discontinuous galerkin method, we do not assume that the triangle sides be bounded away from the characteristic direction. the unique stability follows from the inf-sup condition established on the finite dimensional spaces for the (incompressible) Stokes problem. An error analysis having a jump discontinuity for pressure is shown.

  • PDF

물분사 추진기 관내 점성유동해석 (Viscous Flow Analysis of the Waterjet Duct)

  • 왕정용;전호환;박일룡;차상명
    • 한국해양공학회:학술대회논문집
    • /
    • 한국해양공학회 2000년도 추계학술대회 논문집
    • /
    • pp.68-72
    • /
    • 2000
  • In the present paper, the numerical calculations for the viscous duct flow of water jet propulsion systems ship are carried out. The governing equation, incompressible Navier-Stokes equation, is discretized and analysed by a Method with the stcandard turbulence modeling. For the calculations the duct flow which h e intake flows disturbed by the ship, the results dcuhted by the potenti used Numerical results show fairly good agreement with the experimental data

  • PDF

MgO.$P_2O_5$ 유리의 기계적 성질에 미치는 수분의 영향 (Effects of Water on Mechanical Properties of Magnesium Metaphosphate Glass)

  • 강은태;박용완
    • 한국세라믹학회지
    • /
    • 제23권5호
    • /
    • pp.75-80
    • /
    • 1986
  • The mechanical properties were measured for magnesium phosphate glasses containing small amounts of water. The decrease in hardness with increasing water content was resulted from a looser chain structure caused by water. The fracture of these glasses was changed from brittle fracture to plastic deformation as a results of the increased viscous flow with increasing water contents. The extent of any viscous flow or deformation initiating from the crack tips in these glasses could be considered as quite small.

  • PDF