• 한국공간구조학회논문집
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• 제7권4호
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• pp.97-104
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• 2007

교통진동의 영향을 받는 중층건물의 진동특성에 관한 논문이다. 현장진동계측은 진동원과 진동감소대책을 위하여 실시되었다. 시간영역 진동데이터는 버스와 지하철로 인한 건물에 전달된 진동 영향 등의 진동특성을 위하여 이용되었다. 진동대책을 통한 진동감소의 효과 역시 입증할 수 있었다.

• 한국정밀공학회지
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• 제21권5호
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• pp.122-130
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• 2004

In a high-speed and wide operating field optical disk drive, the vibration problem is one of the most important factors to be considered for reliable performance. And a disk misaligned with axis of rotation is a major source of vibration in optical disk drive. Furthermore, this vibration disturbance of the disk spindle system causes failure in the reading and writing process. So to solve this vibration problem, the vibration absorber using rubber mount has been introduced in recent years. In this paper, we have analyzed the simple optical disk drive model with dynamic vibration absorber through dynamic analysis of 12-dof by Recurdyn program and obtained optimal mass and frequency ratios of dynamic vibration absorber of dynamic vibration absorber and the optimal frequency ratio.

• 한국소음진동공학회논문집
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• 제23권10호
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• pp.902-908
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• 2013

The input torque ripple induced by combustion engines is a significant source of NVH(noise, vibration and harshness) problem in automotive transmissions. Because this torque fluctuation is primarily transmitted to the input shaft of automotive powertrains(e.g., automatic transmissions) when the lock-up clutches are closed, a torsional damper with helical springs is generally inserted between engine and transmissions to isolate the input vibratory energy, which is essential for the passenger comfort. The torsional vibration isolator exhibits frequency ranges in which there is low vibration transmissibility. However, the isolation performance is currently evaluated through the static torsional spring characteristics. In this study, the transmissibility of torsional spring dampers, essential dynamic performance index for vibration isolator, is first experimentally evaluated.

• 한국소음진동공학회논문집
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• 제11권8호
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• pp.331-337
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• 2001

The purpose of this study is to analyze the principal causes of vibration problem and find out the method of vibration reduction in a chip-mount system. The principal causes are investigated through measurements of vibration spectrum and model parameters. Modal parameters are obtained by using an experimental model test. Based on the model parameters from experiments. a model of finite element method is formulated. The model presents effective redesign of increasing the natural frequencies in order to reduce the vibration of a chip-mount system. Further, through computer simulation for the behavior of head to be main vibration source, the best acceleration pattern of head movement can be verified to achieve effective head-positioning and reduce the vibration due to head movement.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.984-989
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• 2000

This paper deals with an analysis and countermeasure of escalator vibration. The vibration characteristics of escalators are studied theoretically and experimentally to find the main cause of severe vibration. The main source of vibration in escalators is found to be chordal effect due to the step chain and sprocket system. It is also found that the vibration become significantly large at so called no load condition, in which the load due to passengers, during down-moving, is equal to the resistive force in the driving system. Dynamic absorbers are implemented to suppress the vibration. A theoretical analysis is made to determine the appropriate dynamic absorber. Theoretical and experimental study shows that dynamic absorber is effective to suppress the vibration in escalators.

• 한국소음진동공학회논문집
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• 제17권12호
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• pp.1145-1151
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• 2007

In this paper, vibration sources of an electric forklift are identified and the forklift vibrations are reduced by structural modification. For vibration identification, vibration signals are measured by an accelerometer when the forklift is moving. These signals are presented in a waterfall plot in order to find the dependency of frequency components on the forklift speed. It is found that main vibration source is tire pattern excitation. From some experiments and finite element analyses, it is also found that resonances occur because the natural frequencies of the forklift exist in usual driving speed range. To shift the natural frequencies outside the driving speed range, the connection parts between main body and loader are modified to increase stiffness. It is verified that considerable amount of vibration are reduced by the structural modification.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 추계학술대회 논문집
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• pp.797-802
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• 2011

Vibration of diesel engines in naval vessels causes structure vibration which is significant under water radiating noise source under CIS (Cavitation Inception Speed). So managing the vibration level of diesel engine is important for survivability and also durability of naval vessels. Therefore, in this research, a vibration criterion which is applied for Korean naval vessels are reviewed. It is compared with the DNV, ABS and merchant ship's diesel engine criteria. And also vibration data of three Korean naval vessels are analyzed. As a result, reasonable criteria of diesel engine vibration and shipbuilding standards are suggested.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.466-469
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• 2002

The vibration measurement of the AC motor, the most typically used vibration source, is essential to evaluate the causes of unexpected excessive vibration in many mechanical systems. The motor contributes to excite the resonance of the mechanical systems, and in turn tilt amplified vibration of the mechanical parts cause the motor to vibrate severely. Without the vibration evaluation on the motor itself, it is time consuming to solve the vibration problems. This paper deals the vibration measurement method for the AC motor itself.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.1089-1094
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• 2003

A main vibration source in HDD is arisen from high rotating disk/spindle, and vibration suppression of the disk-spindle system becomes a critical issue and a major concern for high performance of the drive. In this paper, we study the feasibility of suppressing unwanted vibration of disk-spindle system of the HDD by external shock and excitation utilizing piezoelectric shunt damping methodology. By considering dynamic characteristics of the disk-spindle system through modal analysis, a target vibration mode is determined and then the piezoelectric material is carefully integrated to the modified drive. In order to maximize improvement of vibration characteristics of the proposed system, shunt circuit is optimally designed via tuning processes. Finally, the vibration characteristics of the high rotating disk-spindle system of the proposed drive is experimentally evaluated in frequency domain.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.812-816
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• 2014

Recently, there is an increasing interest on railway noise and vibration. Accordingly, the importance of technology that can assess the vibration and structural noise caused due to the railway operation is increasing. Additionally, the need to construct a railway noise and vibration database which is a basic data for a reliable railway noise and vibration assessment as well is increasing. However, the problem is that the currently constructed database fails to include the factors influencing the occurrence of noise and vibration sufficiently. Therefore, In this paper, design a railway noise and vibration database that includes those factors sufficiently and which enables the continuous data management and accumulation.