• 터널과지하공간
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• 제9권1호
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• pp.36-47
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• 1999

세심한 제어발파를 위해서는 발파진동의 특성을 이해하는 것은 필수적이다. 본 연구에서는 진동이력분석을 응용하여 진동파의 특성을 조사하기 위해 몇가지 실험이이루어졌다. 충격진동과 자유진동의 구분, 지속시간, 진동의 크기에 대한 자유진동의 중첩효과, 지발당량의 증가에 따른 진동파의변화 등이 파형분석과 함께 연구되었다.

• 한국소음진동공학회논문집
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• 제19권5호
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• pp.491-498
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• 2009

This paper deals with structural analysis and vibration characteristics of scaffolding structures with a hoist according to payloads. In order to analyze the vibrational and structural characteristics for 20-step scaffolding structure, structural and vibrational characteristics for 2-step scaffolding structure were compared with some experimental results. The numerical results for natural frequencies of scaffolding structures have a good agreement with experimental ones. Through the numerical analysis, firstly, it is shown that the maximum stress of scaffolding structures is lower than von-mises yield criteria when four persons with total weight of 280 kgf are working at the top of the scaffolding structures. Secondly, vibration characteristics including natural frequencies and modes for scaffolding structures are shown in case of various kinds of moving masses.

• 한국정밀공학회지
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• 제16권2호통권95호
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• pp.183-193
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• 1999

In the previous study, a module-type vibration analysis system using modular approach is developed for the purpose of analyzing the torsional vibration of vehicle driveline. In the present paper, the system is utilized to investigate the torsional vibration of the driveline of a middle duty truck. The driveline with driving condition is modeled and the torsional vibration response is simulated. The resonance 45Hz is found at engine speed 900rpm and the resultant vibration is very high. It shows favorable agreements with reference data. The effects of parameter change on torsional vibration are also investigated, so it is clarified that clutch characteristics, axle shaft stiffness are very influential on reduction of vibratio. So the countermeasure is proposed for the clutch characteristics. The reduction of torsonal vibration by 8rad/sec is obtained.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.169-174
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• 2012

Reduction unit is one of the most important components for railway vehicle because torque of motor must be transmitted to wheels of vehicle by reduction unit. However, According to advanced studies, it has been often broke down due to the damage, fatigue and wear of gear. To solve this problem, defect diagnosis methods of gear have been mainly using the vibration diagnosis technology through vibration waveform and frequency analysis. However, We should know vibration characteristics of normal state reduction unit prior to defect diagnosis. So in this paper, We had analyzed vibration characteristics of reduction unit in order to utilize monitoring system development. Comparison of targets is the vibration characteristics of normal state reduction unit about Electric Multiple Unit(EMU) and the High-speed trains(KTX, KTX II).

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.792-798
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• 2012

This study shows the vibration characteristics of an actuator with six wire-suspensions, used in optical pickups of optical disc drives (ODDs). In this paper, the vibration characteristics of this beam structure is induced mathematically. To obtain vibration modes of focusing direction, the vibration analysis is achieved in lateral and longitudinal directions of the structure. The accuracy of induced vibration characteristics is proved by comparing mode frequencies with a finite element analysis. Finally, it is shown that mode shapes can be modified by changing design parameters in mathematical expressions.

• 한국안전학회지
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• 제16권1호
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• pp.25-30
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• 2001

This paper studies the effect of vibration characteristics of tube line conveying fluid with the power steering system of bus. We modelled fluid-filled tube line using I-DEAS software to investigate vibration characteristics of the power steering tube line. And we obtained the natural frequency of tube line through finite element analysis. Analytic solutions were compared with experimental solutions to verify finite element model. We tested the tube line to examine an effect of pressure pulse by vane pump and variation of geometry of tube. From both the experimental results and the modeling results for vibration characteristics of the tube line conveying fluid, we confirmed that vibration characteristics induced by pulse propagated along the power steering tube line and resonance occurred around the natural frequency with pulse excitation.

• 소음진동
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• 제5권3호
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• pp.395-402
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• 1995

In general low frequency vibration characteristics like an idleshake is mainly influeced by pillar section properties and joints. So the design technique development of vehicle pillar structures is required to initial design and vehicle development stage. In this paper to develop pillar structure design technique considering low frequency vibration characteristics, strain energy method, design sensitivity analysis method, and design optimization method using commercial finite element analysis program and optimization program are presented.

• Smart Structures and Systems
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• 제24권4호
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• pp.525-539
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• 2019

In this study, vibration characteristics of a gravity-based caisson-foundation breakwater system are investigated for ambient and geometric parameters such as various waves, sea levels, and foundation conditions. To achieve the objective, following approaches are implemented. Firstly, operational modal analysis methods are selected to identify vibration modes from output-only dynamic responses. Secondly, a finite element model of an existing caisson-foundation breakwater system is established by using a structural analysis program, ANSYS. Thirdly, forced vibration analyses are performed on the caisson-foundation system for two types of external forces such as controlled impacts and wave-induced dynamic pressures. For the ideal impact, the wave force is converted to a triangular impulse function. For the wave flow, the wave pressure acting on the system is obtained from wave field analysis. Fourthly, vibration modes of the caisson-foundation system are identified from the forced vibration responses by combined use of the operational modal analysis methods. Finally, vibration characteristics of the caisson-foundation system are investigated under various waves, sea levels, and foundations. Relative effects of foundation conditions on vibration characteristics are distinguished from that induced by waves and sea levels.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1994년도 봄 학술발표회 논문집
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• pp.89-94
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• 1994

Latticed domes take form a curved surface by arranged members with certain patterns. For this reason, it is possible for the characteristics of vibration to complicate by change of various parameters of dome; grid-pattern, boundary condition and ratio of radius-height etc. Therefore, it is important to clarify the effect by these parameters before generalized dynamic response analysis. So this study deals with free vibration analysis of latticed domes and makes clear an effect of shape coefficient, that is, geometrical characteristics of latticed domes, on the vibration characteristics.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.946-969
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• 2003

Vibration analysis for a coupled MEMS gyroscope design is presented in this paper. MEMS gyroscopes have shown that slight mistuning in fabricated process often leads to significant difference of vibration characteristics between expected and real designs. The difference frequently affects the MEMS gyroscope design in a negative way. As long as the coupling between excited and sensed motions exists, such difference occurs inevitably. In this paper, dimensionless parameters that govern the vibration characteristics of coupled MEMS gyroscope are identified and the effects of the parameters on the vibration characteristics are investigated for the design of the MEMS gyroscope.