• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.634-639
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• 2006

Active control method is applied to a flexible beam excited by a shock impulse in order to reduce the residual vibrations after the shock event. It is assumed that the shock input can be measured and is always occurred on the same point of the beam. If the system is well identified and the corresponding inverse system is designed reliably, it has shown that a very simple feed-forward active control method may be applied to suppress the residual vibrations without using error sensors and adaptive algorithm. Both numerical simulations and experimental results show a promising possibility of applying to a practical problem. Also, the performance of the method is examined by considering various practical aspects : shock duration, shock magnitude, and control point.

• 한국소음진동공학회논문집
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• 제16권6호
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• pp.651-657
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• 2006

Active control method is applied to a flexible beam excited by a shock impulse in order to reduce the residual vibrations after the shock event. It is assumed that the shock input can be measured and is always occurred on the same point of the beam. If the system is well identified and the corresponding inverse system is designed reliably, it has shown that a very simple feed-forward active control method may be applied to suppress the residual vibrations without using error sensors and adaptive algorithm. Both numerical simulations and experimental results show a promising Possibility of applying to a practical problem. Also, the performance of the method is examined by considering various practical aspects : shock duration, shock magnitude, and control point.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.389.2-389
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• 2002

Nonlinear aeroelastic characteristics of a missile control surface are investigated in this study. The wing model has freeplay structural nonlinearity at its pitch axis. Nonlinear aerodynamic flows with unsteady shock waves are also considered in high-speed flow region. To effectively consider a freeplay structural nonlinearity, the fictitious mass method (FMM) is applied to structural vibration analysis based on finite element method (FEM). (omitted)

• 소음진동
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• 제11권1호
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• pp.41-48
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• 2001

This paper presents vibration control performance of a passenger vehicle featuring magneto-rheological (MR) suspension units. As a first step, a cylindrical shock absorber is designed and manufactured on the basis of Bingham Property of a commercially available MR fluid. After verifying that the damping force of the shock absorber can be controlled by the intensity of magnetic field(or input current), it is applied to a full-car model. An optimal controller is then formulated to effectively suppress unwanted vibration of the vehicle system. The control performances are evaluated via hardware-in-the-loop simulation(HILS), and presented in both time and frequency domains.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.375-380
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• 2004

Seismic Isolation and Shock/vibration Control Laboratory has performed the National Research Laboratory(NRL) project, 'Design and Application of Control Devices against Earthquake/Shock/Vibration'. In this project, the prototypes of the vibration control devices for structural control against earthquake and wind were developed and verified their performances. And also, the computer programs were developed for the seismic response analysis and the optimum design of the base-isolated structures with vibration control devices. This paper introduces the developed vibration control devices and computer programs.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 춘계학술대회 논문집
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• pp.545-547
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• 2014

The scope of ISO/TC 108/SC 6, revised in accordance with Doc. ISO/TC 108/SC 6 N 35, September 1997, is as follows: Standardization in the field of vibration and shock generating systems, for test purposes (including environment, seismic and dynamic testing, calibration and diagnostics) as well as auxiliary equipment and instrumentation normally associated with it. Vibration and shock generating systems as an object of standardization within ISO/TC 108/SC 6 are only those systems that are used during vibration/shock testing to determine properties of a specimen. Vibration and shock systems being used in such processes as transportation, milling, compacting, metal working, etc., as parts of vibration control systems or household appliances and in health services, are not covered by ISO/TC 108/SC 6.

• 드라이브 ㆍ 컨트롤
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• 제18권4호
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• pp.65-71
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• 2021

In this paper, the development of a vibration reduction device for hydraulic breakers was studied. Generally, a hydraulic breaker generates shock vibrations while working. When using vibration-proof rubber, shock vibrations are reduced, but without this, shock vibrations are repeatedly generated. Such repeated shock vibrations not only lower the fatigue strength of hydraulic breakers and excavators equipped with them but also increase the fatigue of the workers. This paper proposes the possibility of reducing shock vibration by using a dynamic vibration absorber.

• 한국안전학회지
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• 제13권4호
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• pp.102-112
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• 1998

Shock absorber has a great influence on the performance of the vehicle(ride comfort, manipulation, noise, vibration, turning, stability). Therefore, in this study we consider theoretically about general damper, variable damping oil damper, the control of vehicle Characteristics for the suspension, and undesirable phenomenon. And we measured the vibration/noise characteristics of shock absorber for the real car experimentation, strain change, and noise characteristics of shock absorber using experimental equipment. The study of domestic company and research institute on the vehicle shock absorber is active, but that of basis is not. So we think that they should be accomplished actively. Therefore, this paper will develop theoretical system on the vibration/noise characteristics of shock absorber by theoretical consideration and experimental result analysis of dynamic characteristics of shock absorber that were accomplished in this study. Then we will use it as the optimistic design data for shock absorber development.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.1111-1116
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• 2001

A transient T-F(time-frequency) signal processing technique is applied to a tilt drop and a linear shock test rigs for identification of shock characteristics of hard disk drive (HDD). The T-F technique essentially tracks the shock characteristics of pivot point response as well as head slap and lift-off phenomena. From the T-F analysis result, the shock characteristic in HDD is modeled by the two degree of freedom coupled-dynamic system, which consists of actuator arm and suspension. As shock designing tool, the maximax shock response spectrum is employed for prediction of shock performance. Finally, the shock control technique is tested with newly designed actuator arm and suspension. Experimental head slap test result shows that the shock performance is much higher with the new shockproof designed model than the current model

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.648-654
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• 2011

The feed-water piping system constitutes a complex flow impedance network incorporating dynamic transfer characteristics which will amplify some pulsation frequencies. Understanding pressure pulsation waves for the feed-water recirculation piping system with cavitation problem of flow control valve is very important to prevent acoustic resonance. Feed water recirculation piping system is excited by potential sources of the shock pulse waves by cavitation of flow control valve. The pulsation becomes the source of structural vibration at the piping system. If it coincides with the natural frequency of the pipe system, excessive vibration results. High-level vibration due to the pressure pulsation affects the reliability of the plant piping system. This paper discusses the piping vibration due to the effect of shock pulsation by the cavitation of the flow control valves for the recirculation piping of feed-water pump system in combined cycle power plants.