• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.33-48
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• 2000

Limitations of the simple single degree of freedom vibration isolation theory in real applications are discussed and a theory of multi-dimensional vibration/noise isolation by power approach is introduced. Illustrations of the application to compressor of an air-conditioner are presented together with problems caused by approximations. Then possible sources of distortions in the vibration power estimation are looked into and some relevant research topics are suggested.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.836-839
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• 2005

The in-plane vibration response of a clamped circular plate should be predicted in many applications. Up to now, papers on the in-plane vibration of rectangular plate are published. However, analytical derivation on the in-plane vibration of the clamped circular plate is not carried out. Therefore, the in-plane vibration of the clamped circular plate is the concern of this paper. In order to derive the equations of motion for the clamped circular plate in the cylindrical coordinate, the kinetic energy and potential energy for the in-plane behavior are obtained by us ing the stress-strain-displacement expressions. Application of Hamilton's principle leads to two sets of differential equations. These displacement equations were highly coupled. It is possible to obtain a simpler set of equations by introducing Helmholtz decomposition. Substituting them into the coupled differential equations, we obtain the uncoupled equations of motion. In order to solve them, we assume that the solutions are harmonic. Then, they lead to the wave equations. Using the separation of variable, we obtain the general solutions for the equations. Based on the solutions, the displacements for r and $\theta$ direction are assumed. Finally we obtain the frequency equation for the clamped circular plate by the application of boundary conditions. The derived equation is compared with the finite element analysis for validation by using the some numerical examples.

• Journal of Korean Association for Spatial Structures
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• v.15 no.4
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• pp.99-105
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• 2015

The serviceability design of the high-rise building is affected by the wind response vibration such as the acceleration, at this time it is important to calculate the natural frequency correctly. Since the suggestion equation of the natural frequency being used in the design phase is not the regression equation obtained from the vibration measurement of the high-rise building, the verification to use for the serviceability design of the high-rise building is necessary. This thesis conducted an ambient vibration measuring on the high-rise building through the mobile-phone application to calculate the natural frequency and suggested a natural frequency approximate expression following the building's height, and compared with the domestic/foreign standard and the result of the eigen-value analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.774-781
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• 2006

This paper presents a study on the analytical prediction of vibration transmission from helical gears to the bearing. The proposed method is based on the application of the three dimensional helical gear behaviors and complete description of shaft by the spectral method. Helical gear system used in this paper consists of the driving element, helical gears, shafts, bearings, couplings and load element. In order to describe all translation and rotation motion of helical gears twelve degree of freedom equations of motion by the transmission error excitation are derived. Using these equations, transfer matrix for the helical gear is derived. For the detail behavior of shaft motion, the $12{\times}12$ transfer matrix for the shaft is derived. Transfer matrix for the bearing, coupling, driving element, and load is also derived. Application of the boundary conditions in the assembled transfer matrix produces the forces and displacements in each element of the helical gear system. The effect of the proposed method is shown by numerical example.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.72-73
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• 2013

• Journal of KSNVE
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• v.8 no.4
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• pp.700-705
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• 1998

Recent past work has demonstrated that hydraulic semiactive vibration absorbers hold the promise of providing an ideal means of mitigating structural vibration. This paper examines a factor that must be treated when designing a hydraulic semiactive vibration absorber for application to a full scale structure; fluid compressibility. An expanded and consistent dynamic model of the flow process is first established. A simple feedback control is then tested on a single degree of freedom laboratory structure to verify the findings.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.10a
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• pp.371-376
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• 1996

효율적인 진동환경관리를 위해 GIS Software를 사용하여 개발된 진동환경관리시스템(Vibration Management System : VMS)을 점진동원과 선진동원에서의 진동관리에 적용하였다. 점진동원에 의한 진동관리를 위해서는 발파진동을 예로 들었으며, 선진동원의 경우는 지하철 운행시의 교통진동에 의한 인근지역에서의 진동환경을 분석하였다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.7
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• pp.857-864
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• 2016

In the present work, vibration analysis of high speed rotary bell cup model for paint atomizer application is carried out through numerical simulation. At first, eight bell cup models, considering four different cup shapes and two different cup diameters, are proposed and corresponding dynamic characteristics are investigated. To evaluate the operating stability, critical speed analysis is conducted using Campbell diagram and separation margin between operating speed and critical speed is identified. Unbalance vibration responses are also studied according to operating speed and balancing quality grade of G. Finally, the stability and adequacy of the proposed bell cup models are discussed for field application.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.3 s.108
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• pp.307-312
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• 2006

In this study a vibration isolation system with the cradle-type support was designed so as to reduce the transient vibration due to positioning motion of the moving mass on worktable as well as to achieve the desired isolation efficiency on the floor vibration. The design procedure was performed in the two steps. The first step to select appropriate isolators to meet the isolation efficiency, and the second step is to reduce the transient vibration of the worktable by adopting the cradle-type support. After the application of the selected isolators with the cradle-type support to the system it was shown that the required vibration criterion(VC-D) was easily satisfied and that the undesirable transient vibration was reduced remarkably.

• Journal of the Ergonomics Society of Korea
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• v.32 no.4
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• pp.303-308
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• 2013

Objective: The aim of this study is to understand health effect of hand-arm transmitted vibration. Background: Electronic vibration tools have been used in many industries. These tools evoke hand-arm transmitted vibration that cause hand-arm vibration syndrome. Method: Various papers on the hand-arm transmitted vibration and its health effects have been reviewed to know what health effect caused. Results: Hand-arm transmitted vibration causes circulatory, neural, musculoskeletal and other disturbance. Conclusion: The previous studies focused on the epidemiology and physiology for hand-arm transmitted vibration. So, now we should focus on a prevention and guideline of hand-arm transmitted vibration. Application: These results can be used to know health effect of hand-arm transmitted vibration.