• Smart Structures and Systems
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• 제17권5호
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• pp.691-708
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• 2016

Recently, number of smart material are investigated and widely used in civil construction and other industries. Present study investigates the application of smart semi-active piezoelectric friction damper (PFD) made with piezoelectric material for the seismic control of the horizontally curved bridge isolated with lead rubber bearing (LRB). The main aim of the study is to investigate the effectiveness of hybrid system and to find out the optimum parameters of PFD for seismic control of the curved bridge. The selected curved bridge is a continuous three-span concrete box girder supported on pier and rigid abutment. The PFD is located between the deck and abutments or piers in chord and radial directions. The bridge is excited with four different earthquake ground motions with all three components (i.e. two horizontal and a vertical) having different characteristics. It is observed that the use of semi-active PFD with LRB is quite effective in controlling the response of the curved bridge as compared with passive system. The incorporation of the smart damper requiring small amount of energy in addition with an isolation system can be used for effective control the curved bridge against the dynamic loading.

• 한국전산구조공학회논문집
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• 제19권3호
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• pp.233-238
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• 2006

이 논문에서는 소형 다층 구조물의 진동제어에 적용하기 위한 복합모드의 자기유변유체(MR) 감쇠기를 개발하였다. 우선, 도식적으로 전단, 유동, 복합모드 MR감쇠기의 형태를 설계조건과 함께 표현하였고, 각각의 모드에 대하여 자기장에 따른 감쇠력을 예측하기 위한 해석모델을 유도하였다. 다음으로 적당한 크기의 복합모드 MR감쇠기를 제작하고 자기장에 따른 감쇠특성을 시간영역에서 평가하였다. 마지막으로 지진하중을 받는 소형구조물에 제작된 MR감쇠기가 준능동 제어기로 제어하였을 때의 성능을 수치적으로 평가하였다.

• 한국정밀공학회지
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• 제15권6호
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• pp.15-21
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• 1998

Mostly a ride comfort and handling performance of vehicle is influenced by dynamic behavior control of vehicle. We are focusing on development of a semi-intelligent suspension system with continuously variable damper(HS-SH type). only using absolute velocity of sprung mass without using the relative velocity besides having lower system prices and a little energy requirement. In this paper, the system is realized in consideration to control strategy (sky-hook control, hybrid filter, etc.) and has been proved to have improvement of behavior control of vehicle by quarter car and Vehicle test, respectively.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.213-217
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• 1997

The semi-active recoil system provides automatic hydraulic pressure and recoil length by an exteral impulse compared with the conventional recoil system. We developed the proto type of recoil system and validated the performance through simulation and experiment. The main issue of the system is how to adjust pressure and length simultaneously. The system consists of external pressure control valve and flow control valve outside of cylinder. The pressure control valve control the cylinder pressure and recoil length. The controlled system enhances the control performance.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 추계학술대회 논문집
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• pp.234-235
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• 2010

• 한국정밀공학회지
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• 제17권10호
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• pp.69-76
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• 2000

Lots of semi-active control devices have been developed in recent years because they have the best features of passive and active system. Especially, controllable magneto-rheological(MR) fluid devices have received significant attention in these area of research. The MR fluid is the material that reversibly changes from a free-flowing, linear viscous fluid to a semisolid with a controllable yield strength in milliseconds when exposed to a magnetic field. If the magnetic field is induced by moving a permanent magnet instead of applying current to a solenoid, it is possible to design a MR damper consuming low power because the power consumption is reduced at steady state. This paper proposes valve mode MR damper using permanent magnetic circuit that has wide range of operation with low power consumption, a design parameter is adopted. The magnetic circuit, material of choke and choke type are selected experimentally with the design parameter. The behaviors of the damper are examined and torque tracking control using PID feedback controller is performed for step, ramp and sinusoidal trajectiories.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.433-439
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• 2000

Lots of semi-active control devices have been developed in recent years because they have the best features of passive and active system. Especially, controllable magneto-rheological(MR) fluid devices have received significant attention in these area of research. The MR fluid is the material that reversibly changes from a free-flowing, linear viscous fluid to a semisolid with a controllable yield strength in milliseconds when exposed to a magnetic field. If the magnetic field is induced by moving a permanent magnet instead of applying current to a solenoid, it is possible to design a MR damper consuming low power because the power consumption is reduced at steady state. This paper proposes valve mode MR damper using permanent magnetic circuit that has wide range of operation with low power consumption and small size. To design a MR damper that has a large maximum dissipating torque and a low damping coefficient, a design parameter is adopted. The magnetic circuit, material of choke and choke type are selected experimentally with the design parameter. The behaviors of the damper are examined and torque tracking control using PID feedback controller is performed for step, ramp and sinusoidal trajectories.

• 항공우주시스템공학회지
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• 제14권4호
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• pp.10-17
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• 2020

When an aircraft is taxiing, excitation force is applied according to the shape of the road surface. The sprung mass acceleration caused by the excitation of the road surface negatively affects the feeling of boarding. This paper addresses the verification process of the semi-active control method applied to improve the feeling of boarding. The Magneto-Rheological damper landing gear model is employed alongside the control method. It is a Oleo-Pneumatic damper filled with a fluid having the characteristics of increasing yield stress when subjected to a magnetic field. The control method involves verifying Skyhook Control Type2 developed by Skyhook control. The Sinozuka white noise model that considers runway characteristics was employed for the road surface in the simulation. The runway road surface obtained through this model has stochastic characteristics, so the dynamic characteristics were analyzed by applying Monte-Carlo simulation. A dynamic analysis was conducted by co-simulating the landing gear model made by RecurDyn and the control method designed by Simulink. Simulation results show that the Skyhook Control Type2 method has the best control effect in the low speed range compared to the passive type (without control) and skyhook control.

• Smart Structures and Systems
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• 제1권2호
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• pp.159-184
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• 2005

The paper intends to summarize some guidelines for future smart structure system application in military aircraft. This preview of system integration is based upon a review on approximately one and a half decades of application oriented aerospace related smart structures research. Achievements in the area of structural health monitoring, adaptive shape, adaptive load bearing devices and active vibration control have been reached, potentials have been identified, several feasibility studies have been performed and some smart technologies have been already implemented. However the realization of anticipated visions and previously initial timescales announced have been rather too optimistic. The current development shall be based on a more realistic basis including more emphasis on fundamental aircraft strength, stiffness, static and dynamic load and stability requirements of aircraft and interdisciplinary integration requirements and improvements of integrated actors, actuator systems and control systems including micro controllers.

• 한국지진공학회논문집
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• 제9권1호통권41호
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• pp.51-59
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• 2005

본 연구에서는 위의 어려움을 해결하기 위해, 스마트 수동제어 시스템을 제안하였다. 스마트 수동제어 시스템은 MR댐퍼와 EMI시스템으로 구성되며, EMI시스템은 영구자석과 솔레노이드 코일로 이루어진다. EMI시스템은 MR댐퍼의 왕복운동에너지를 전기에너지로 변환하므로, 스마트 수동제어 시스템은 외부 전원 없이 외부하중에 따라 댐퍼의 점성을 바꾸는 적응성을 갖는다. 따라서 간단하고 효율적인 장치로써, 대형토목구조물에 적용 가능하다. 이의 확인을 위해 예제를 통한 수치해석을 수행하였으며, 스마트 수동제어 시스템이 강진에 대해서는 기존의 반능동 제어 MR댐퍼 시스템 보다 우수한 성능을 보인다.