• 제목/요약/키워드: Damper Size

검색결과 79건 처리시간 0.174초

점탄성 감쇠기의 간극 변화에 따른 동특성에 대한 실험적 연구 (Experimental research of dynamic behaviors at viscoelastic damper with change of orifice)

  • 윤종민;임상혁;박화용;김창열;이재응
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2011년도 춘계학술대회 논문집
    • /
    • pp.744-749
    • /
    • 2011
  • Silicon oil in viscous fluid damper has a viscoelastic feature that show stiffness besides damping. These properties depend on frequency and are non-linear. A lot of research has been conducted in order to identify viscoelastic damper with mathematical model. Fractional Derivative Maxwell Model has been widely used, but this model did not explain the effect of damper size change on the damper performance. In this paper, the experimental study was conducted to validate damper's dynamic behaviors when total damper's size is changed while maintaining same aspect ratio and orifice size.

  • PDF

Incorporating magneto-Rheological damper into riser tensioner system to restrict riser stroke in moderate-size semisubmersibles

  • Zainuddin, Zaid;Kim, Moo-Hyun;Kang, Heon-Yong;Bhat, Shankar
    • Ocean Systems Engineering
    • /
    • 제8권2호
    • /
    • pp.101-118
    • /
    • 2018
  • In case of conventional shallow-draft semisubmersibles, unacceptably large riser stroke was the restricting factor for dry-tree-riser-semisubmersible development. Many attempts to address this issue have focused on using larger draft and size with extra heave-damping plates, which results in a huge cost increase. The objective of this paper is to investigate an alternative solution by improving riser systems through the implementation of a magneto-rheological damper (MR Damper) so that it can be used with moderate-size/draft semisubmersibles. In this regard, MR-damper riser systems and connections are numerically modeled so that they can couple with hull-mooring time-domain simulations. The simulation results show that the moderate-size semisubmersible with MR damper system can be used with conventional dry-tree pneumatic tensioners by effectively reducing stroke-distance even in the most severe (1000-yr) storm environments. Furthermore, the damping level of the MR damper can be controlled to best fit target cases by changing input electric currents. The reduction in stroke allows smaller topside deck spacing, which in turn leads to smaller deck and hull. As the penalty of reducing riser stroke by MR damper, the force on the MR-damper can significantly be increased, which requires applying optimal electric currents.

MR Damper의 Gap Size에 따른 제어성능 분석 (Analysis of Control Performance in Gap Size of MR Damper)

  • 허광희;전승곤;서상구;김대혁
    • 한국구조물진단유지관리공학회 논문집
    • /
    • 제25권1호
    • /
    • pp.41-50
    • /
    • 2021
  • 본 연구에서는 MR Damper의 제어력을 결정하는 다양한 요인들 중, 유로폭(Gap Size)을 다르게 선정하여 그에 따른 제어력의 변화를 확인하였다. 이를 위해 Gap Size 1.0mm, 1.5mm인 MR Damper 두 대를 제작하고 인가전류와 가진조건을 정하였으며 그에 따른 동하중 실험을 수행하였다. 실험결과 최소제어력은 Gap Size 1.0mm 조건이 Gap Size 1.5mm 조건보다 3.2배 높았으며 최대제어력은 Gap Size 1.0mm 조건이 Gap Size 1.5mm 조건보다 2.3배 높았다. 또한, 인가전류에 따른 제어력의 증가폭은 Gap Size 1.0mm일 때 34N, Gap Size 1.5mm일 때 12.7N으로 나타났다. Gap Size가 커질수록 전체 제어력과 인가전류에 따른 제어력의 증가는 감소하였다. 두 개의 MR Damper의 동적범위를 확인해 본 결과 Gap Size 1.0mm일 때 평균 2.3, Gap Size 1.5mm일 때 평균 2.8인 것을 볼 때 두 MR Damper의 준능동제어장치로써 사용가능성을 확인하였다.

점성 유체 감쇠기의 크기 변화에 따른 성능 변화 예측 (Prediction of the Ability of a Viscous Fluid Damper with Respect to Change of the Size of the Damper)

  • 박화용;윤종민;유성환;김창열;이재응
    • 한국소음진동공학회논문집
    • /
    • 제22권1호
    • /
    • pp.53-60
    • /
    • 2012
  • To reduce the vibration in industrial settings, the viscous fluid dampers have been widely used. Since the damper shows a viscoelastic behavior, many methods to predict the behavior have been investigated. But the methods did not consider a change of damper size that is important factor for practical design engineer. In this study, to predict a change of damper ability with respect to a change of damper size, the dynamic experiment were conducted with fixed aspect ratio and gap. The damping coefficient at zero frequency was computed through theoretical and experiment approach in order to fit the experimental results using fractional derivative Maxwell model.

MR 유체를 이용한 운전석 댐퍼의 성능특성 (Performance Characteristics of Seat Damper Using MR Fluid)

  • 남무호
    • 한국생산제조학회지
    • /
    • 제9권5호
    • /
    • pp.127-134
    • /
    • 2000
  • This paper presents the development of a semi-active seat damper using MR fluids and the performance analysis of seat suspension system with a MR seat damper. An annular orifice type MR seat damper is proposed for a seat suspension of a commercial vehicle. After formulating the governing equation of motion, then an appropriate size of the seat damper is designed and manufactured. Following the evaluation of field-dependant damping force characteristics, the controllability of the damping force is experimentally demonstrated in time domain by adopting PID controller. A semi-active seat suspension with the proposed MR damper is constructed and its dynamic model is established. Subsequently, vibration control capability of the semi-active suspension system is investigated by employing the sky-hook controller.

  • PDF

리버스 무단 댐퍼용 연속가변밸브의 튜닝 파라미터에 관한 연구 (A Study on the Tuning Parameter of Continuous Variable Valve for Reverse Continuous Damper)

  • 윤영환;최명진;유송민
    • 한국자동차공학회논문집
    • /
    • 제10권3호
    • /
    • pp.192-200
    • /
    • 2002
  • Semi-active suspension systems are greatly expected to be in the mainstream of future controlled suspensions for passenger cars. In this study, a continuous variable damper for a passenger car suspension is developed, which is controlled actively and exhibits high performance with light weight, low cost, and low energy consumption. To get fast response of the damper, reverse damping mechanism is adapted, and to get small pressure change rate after blow-off, a pilot controlled proportional valve is designed and analyzed. The reverse continuous variable damper is designed as a HS-SH damper that offers good body control with reduced transferred input force from tire, compared with any other type of suspension system. The damper structure is designed, so that rebound and compression damping force can be tuned independently, of which variable valve is placed externally. The rate of pressure change with respect to the flow rate after blow-off becomes smooth when the fixed orifice size increases, which means that the blow-off slope is controllable using the fixed orifice size. The damping force variance is wide and continuous, and is controlled by the spool opening, of which scheme is usually adapted in proportional valves. The reverse continuous variable damper developed in this study is expected to be utilized in the semi-active suspension systems in passenger cars after its performance and simplicity of the design is confirmed through real car test.

ER 유체를 이용한 반능동식 가변댐퍼의 성능해석 (Performance Analysis of a Semi-Active Variable Damper Featuring Electro-Rheological Fluids)

  • 최승복;정재천;최용빈;허승진;서문석
    • 한국자동차공학회논문집
    • /
    • 제1권1호
    • /
    • pp.90-100
    • /
    • 1993
  • This paper presents some inherent characteristics of a semi-active variable damper featuring electro-rheological (ER) fluid. The damping force of the damper can be selectively adjusted or controlled by employing electric field to the ER fluid domain. This is possible owing to the pressure drop across the piston occured by field-dependent variable yield stress of the ER fluid. This is fundamentally different than the performance of a conventional adjustable viscous damper. To demonstrate the effectiveness and superiority over the conventional one, the proposed damper is incorporated with a suspension system. A quarter car model with the suspension system is formulated and represented by a state equation. By choosing numerical values based on realistic package size, power requirements and suitable ER properties, the performance characteristics of the suspension system are obtained and evaluated in both frequency and time domains. The effects of constant electric field and on-off controlled electric field which relates to the damping force are also examined.

  • PDF

MR 시트댐퍼를 장착한 상용차의 제어성능 평가 (Performance Evaluation of Commercial Vehicle with MR Seat Damper)

  • 성금길;이호근;남무호;최승복
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2003년도 춘계학술대회논문집
    • /
    • pp.1048-1053
    • /
    • 2003
  • This paper proposed a MR(Magneto-rheological) seat damper for a commercial vehicle. After formulating the governing equation of motion, an appropriate size of damper is designed and manufactured. Following the equation of fie d-dependent damping force characteristics, a semi-active seat suspension installed with the proposed MR-damper is constructed and its dynamic model id established, Subsequently, vibration isolation performance of the semi-active suspension system is demonstrated by incorporating with a MRAC(Model referenced adaptive control) fer the MR Seat Damper

  • PDF

등방성 감쇠장치를 갖는 KGDS시스템을 활용한 라멘조 건물의 제진효과 (Vibration Control of the Framed Building Structures Using KGDS System with Isotropic Damping Devices)

  • 허무원;이상현;천영수
    • 한국구조물진단유지관리공학회 논문집
    • /
    • 제19권2호
    • /
    • pp.52-59
    • /
    • 2015
  • 본 논문에서는 효과적인 제진설계를 구현하기 위한 설계기술 개발의 일환으로 20층 라멘조 형식의 공동주택을 대상으로 최근 개발된 등 방성감쇠장치 (일명 카고메감쇠장치)를 적용하여 대상구조물-카고메감쇠장치-지지구조물로 구성된 새로운 형식의 시스템 (Kagome Damper System : KGDS)을 제안하고, 대상구조물과 지지구조물의 강성차, 감쇠장치의 크기 및 지지구조물의 적용 층수 등을 변수로 수치해석을 수행하여 제진효과를 검토해 보았다. 해석결과, 밑면전단력과 최상층 최대응답변위 감소라는 관점에서 유효한 제진효과를 얻기 위해서는 지지구조물을 3개층 높이로 설치할 경우, 대상구조물과 지지구조물 간의 강성비는 약 6.4배 이상, 감쇠장치의 사이즈는 $700{\times}700mm$ 이상을 확보할 필요가 있으며, 지지구조물을 5개층 높이로 설치할 경우에는 대상구조물과 지지구조물 간의 강성비는 약 7.0배 이상, 감쇠장치의 사이즈는 $500{\times}500mm$ 이상을 확보할 필요가 있는 것으로 판단된다.

복합모드형 소형 MR감쇠장치 성능에 관한 실험적 연구 (An Experimental Study on the Performance of a Mixed Mode Type Small Scale MR Damper)

  • 이상현;민경원;이명규;박은천
    • 한국지진공학회:학술대회논문집
    • /
    • 한국지진공학회 2005년도 학술발표회 논문집
    • /
    • pp.461-468
    • /
    • 2005
  • In this paper, mixed mode magneto-rheological (MR) damper, which is applicable for vibration control of a small scale multi-story structure, is devised. First, the schematic configurations of the shear, flow, and mixed mode MR dampers are described with design constraints and then the analytical models to predict the field-dependent damping forces are derived for each type. Second, an appropriate size of the mixed mode MR damper is manufactured and its field-dependent damping characteristics are evaluated in time domain. Finally, the performance of the manufactured MR damper which is semi-actively applied to a small scale building excited by earthquake load, is numerically evaluated.

  • PDF