• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.459-463
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• 2002

ER mount can be used instead of rubber mount in cylindrical shell to improve the vibration and noise performance. The noise radiated by cylindrical shell will be reduced by reducing the force transmitted to the cylindrical shell through ER mount. In this paper LQ control theory is used to reduce the transmitted force to the cylindrical shell. The finite element method of cylindrical shell is formulated by NASTRAN and its vibrating shape is calculated in frequency domain. The noise radiated from the cylindrical shell is calculated by the use of SYSNOISE, the boundary element CAE tool. The vibration of the cylindrical shell and radiated acoustic pressure is compared in case of both controlled and uncontrolled ER mount.

• 한국소음진동공학회논문집
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• 제11권8호
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• pp.374-383
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• 2001

A reciprocating compressor unit with variable rotating speed driven by BLDC motor is mounted Inside hermetic chamber on an internal suspension composed of 4 roil springs and a discharge pipe. A method for predicting the dynamic behavior of compressor body is required for a reduction of transmitted vibrations. The mechanical characteristics of spring and discharge pipe stiffness properties have been obtained from experimental tests and mass moment of inertia of the compressor body iron CAD. To confirm the vibration model for the compressor body, free vibration analyses are performed with theoretical and experimental methods. results for analytical investigations on the dynamic behavior of the compressor body and the transmitted forces to the hermetic chamber through the suspension elements are Presented.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.348.2-348
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• 2002

ER mount is often used instead of rubber mount in cylindrical shell to improve the vibration and noise performanec. The noise radiated by cylindrical shell will be reduced by reducing the force transmitted to the cylindrical shell through ER mount. In this paper, LQ control theory is used to reduce the transmitted force to the cylindrical shell. The finite element method of cylindrical shell is formulated by NASTRAN and its vibrating shape is calculated in frequency domain. (omitted)

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.1032-1037
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• 2003

This work measured the hand-transmitted vibration due to shipyard worker's grinding and assessed the vibration exposure for predicted 10% prevalence of vibration-induced white finger in a group of exposed persons according to test procedure of ISO 5349-1. And also the transmissibility performance of resilient material, mainly applied to anti-vibration gloves in present market was measured on the basis of ISO 13753 and confirmed that the material would Probably not provide greater attenuation below 30㎐, the dominant frequency range of hand-transmitted vibration due to grinder.

• 소음진동
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• 제2권4호
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• pp.281-292
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• 1992

Two types of vibration problems are encountered in industrial field: active isolation and passive isolation. In a passive type of vibration isolation, a foundation of a delicated machinery such as TEM, SEM, inspection- probe test, photolithograph, etc. is designed to have a vibration amplitude lower than an acceptable limit. In an active type, the isolation is focused on the vibration reduction caused by the machine itself(pump, motor, press, compressor, etc.). The foundation for such a machine should be so designed as to reduce the transmitted vibration below the permissible level prescribed. At any case, a transmissibility and stability must to be considered. Since an active isolation type is aimed for a vibration source, it is useful to isolate the transmitted vibrations energy from a major vibration source at the specific location. In this paper, a designed methodology of double anti-vibration system has been examined in order to have low transmissibility and reliable stability. Also experiment of scale model behavior has been conducted. Finally, the experiment output of the transfer function is compared to the analytical data.

• 한국소음진동공학회논문집
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• 제24권8호
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• pp.592-599
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• 2014

A torsional vibration at driveline happens seriously at rapid vehicle acceleration. The torsional vibration at driveline can be reduced by optimization of joint angle and yoke phase angle of driveline. But, the joint angle of driveline is changed according to vehicle driving condition as acceleration, deceleration, forward and backward driving, so that excessive vibration is transmitted to vehicle body at specific driving condition. Especially under rapid acceleration condition, vibration transmitted to body could be maximized because excitation force at rapid acceleration is bigger than that at normal driving condition due to changed joint angle. The torsional vibration of driveline can be kept at low level by controlling suspension parameter to minimize rigid axle displacement as well as optimizing joint angles considering the vehicle acceleration condition.

• 한국철도학회논문집
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• 제10권1호
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• pp.45-50
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• 2007

When the walls and floor of a tunnel are excited by a train, a ground vibration energy is transmitted to the surface and to footing of a nearby buildings. Excessive vibration affected to a building structure causes undesirable effect to the structural safety and the perception on residents in building. In this paper, a simple approach is introduced to predict how much vibration, in terms of level and spectra, is transmitted through the ground from the tunnel vibration excitation. A high rise building on a tunnel is selected as an application example of this case study.

• 한국소음진동공학회논문집
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• 제13권1호
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• pp.40-47
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• 2003

This study was conducted to determine the sound paths and transmitted sound level in house. An air-conditioner system was selected a typical sound source. The measured transmission loss data shows that the apertures have an significant effect on the transmitted noise and comparable with the existing theoretical data. Therefore the complex aperture was substitute to quantitative apertures approximately. An effective simulation method, ray tracing and mirror image source method, was employed in the prediction of transmitted sound level. The measured results were efficiently reflected on the simulated results. So it is important that measuring the acoustic parameter prior to the prediction of the transmitted sound level in the house.

• 한국소음진동공학회논문집
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• 제18권11호
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• pp.1177-1184
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• 2008

URN(underwater radiated noise) is one of the important performances of the battle ship related to the stealth. The main source of the URN is the structure-borne noise on the hull. And the pipe vibration transmitted to the hull is the main source of the structure-borne noise when the speed of the ship is lower than CIS(cavitation inception speed). In this paper, the vibration isolator(rubber mount) for the pipe system is described in order to reduce the structure-borne noise transmitted to the hull. The vibrations on the sea-water conveying pipes and their supports are measured in order to know how much vibration occurs on those positions. Based on these test results, the improved design of the rubber mount is suggested by the parametric study and is verified numerically with the pipe and hull model.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 I
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• pp.455-458
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• 2001

In this paper, ISO2631-1(1997) was used to assess the vibration and shock transmitted by train seat with respect to possible effects on human health. Evaluations have been performed on the seat acceleration measured in two type of train, Saemaulho and Mugunghwaho. For each train, limiting daily exposure durations were estimated by comparing the frequency weighted root mean square(i.e., r.m.s) acceleration and the vibration dose values(i.e., VDV), calculated according to ISO2631-1(1997) with exposure limits, health guidance caution zones.