• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1945-1950
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• 2000

When one build a building that posses Precison production process to be sensitive to vibration and SMD to procuce a large dynamic force, how do one predict & answer vibration control problem at building structure design at first stage, That is a question. It has tried to predict dynamic response and establish answering about global or local dynamic problem in building using experimental and analysis method. One of such a try, it be proposed Semi-Empirial Method that reduce error element of input information about dynamic analysis using dynamic experimental study and measurement data in the basis of real-structure. In this paper, the dynamic response problem about RC-structure building that will be set-up SMD produce large transient dynamic force using Semi-Empirical Method.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.5
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• pp.470-476
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• 2010

In this work, the mechanism of structure-borne noise resulting from vibration of a compressor for a refrigerator is experimentally analyzed and an effective method is proposed to reduce the noise. Firstly, the emission noise, when the compressor is turned on and off, is measured and analyzed to identify the generation mechanism of structure-borne noise. And the acceleration on the outer wall of the refrigerator is also analyzed to identify the distribution of vibration. Secondly, an effective design method to reduce the noise is suggested by using the finite element analysis and Taguchi method. Consequently an optimal design of the refrigerator, which has lower noise, is obtained and then its performance and validity are verified through the analysis and test.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1054-1059
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• 2007

This paper summarized a solution procedure for a large cylindrical structure mounted underneath a ship as a sonar. Vibration analysis of the water loaded structure is required to enhance the structural reliability as well as acoustic performance of the sonar. It is, however, often very difficult to solve such structures since they have many DOFs, considering the frequency of interest and the waterloading. The cyclic symmetric method is firstly reviewed to show how the eigen properties of the full model can be obtained from the representative segment model. The mode mapping method is then proposed and verified to take into account the waterloading with the minimum DOF for the analysis. The solution procedure is finally proposed and applied for a waterloaded cylindrical array structure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.232-237
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• 2006

Operation deflection shapes(ODS) is defined as a motion of structure at particular frequency. The ODS is eligible to show any types of structural motions while the modes supply solutions only to linear and stationary motion. The principal vibration source of an auto teller machine(ATM) case was occurred due to resonance which was found by modal analysis. To reduce the vibration of ATM case, the motion of the case was visualized using ODS analysis, which can suggest how to modify the structure. As a result the vibration of the ATM case was greatly reduced with a stiffening bar between the opposite plates.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.3195-3200
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• 2011

The vibration resulting from railway operation is transmitted through the track and line structure, ground movements to adjacent buildings. As these vibration is growing, there is occurred exaggerated forces and displacements of the track and line structure and it is causing the differential settlement. It is difficult to clarify the dynamic response characteristics of trackbed because of various environmental conditions. However, track irregularity be affected by ununiformed bearing capacity and its dynamic response, study for dynamic response characteristics is required to investigate the cause of track irregularity and countermeasure. This study was intended to evaluate the numerical analysis which exam the response analysis characteristic of ground vibration by shape of cutting and embankment transition zone. The original method of analysis were have to examine variables such as directions, angles, drain conditions, linear conditions. However, In the analysis there were to consider the effect of moving loads according to directions of cutting and embankment transition zone.

• Structural Engineering and Mechanics
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• v.13 no.4
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• pp.355-368
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• 2002

In this paper, we address the numerical investigation on the effect of liquid compressibility onto the natural frequency of liquid-filled containers. Traditionally the liquid motion has been treated as an ideal fluid motion. However, from the numerical experiments for the axisymmetrical free-vibration of cylindrical liquid-storage tanks, we found that the relative difference in natural frequencies between ideal and compressible motions becomes remarkable, as the slenderness of tank or the relative liquid-fill height becomes larger. Therefore, in such cases of dynamic systems, the liquid compressibility becomes an important parameter, for the accurate vibration analysis. For the free-vibration analysis of compressible liquid-structure interaction we employed the coupled finite element formulation expressed in terms of the acoustic wave pressure and the structure deformation.

• Journal of Power System Engineering
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• v.2 no.1
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• pp.59-66
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• 1998

The authors have studied vibration analysis algorithm which was suitable to the personal computer. Recently, we presented the transfer stiffness coefficient method(TSCM). This method is based on the concept of the transfer of the nodal dynamic stiffness coefficients which are related to force and displacement vectors at each node. In this paper, we describes the general formulation for the longitudinal and flexural coupled vibration analysis of a beam type structure by the TSCM. And the superiority of the TSCM to the finite element method(FEM) in the computation accuracy, cost and convenience was confirmed by results of the numerical computation and experiment.

• Smart Structures and Systems
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• v.10 no.6
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• pp.517-546
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• 2012

In this paper, vibration-based methods to monitor damage in foundation-structure interface of harbor caisson structure are presented. The following approaches are implemented to achieve the objective. Firstly, vibration-based damage monitoring methods utilizing a variety of vibration features are selected for harbor caisson structure. Autoregressive (AR) model for time-series analysis and power spectral density (PSD) for frequency-domain analysis are selected to detect the change in the caisson structure. Also, the changes in modal parameters such as natural frequency and mode shape are examined for damage monitoring in the structure. Secondly, the feasibility of damage monitoring methods is experimentally examined on an un-submerged lab-scaled mono-caisson. Finally, numerical analysis of un-submerged mono-caisson, submerged mono-caisson and un-submerged interlocked multiple-caissons are carried out to examine the effect of boundary-dependent parameters on the damage monitoring of harbor caisson structures.

• Journal of Power System Engineering
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• v.3 no.1
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• pp.74-79
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• 1999

This paper describes formulation for algorithm of time historical response analysis of vibration for straight-line structure. This method is derived from a combination of the transfer stiffness coefficient method and the Newmark method. And this present method improves the computational accuracy of the transient vibration response analysis remarkably owing to several advantages of the transfer stiffness coefficient method. We regarded the structure as a lumped mass system here. The analysis algorithm for the time historical response was formulated for the straight-line structure containing crooked, tree type system. The validity of the present method compared with the transfer matrix method and the Finite Element Method for transient vibration analysis is demonstrated through the numerical computations.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.6
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• pp.138-144
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• 2010

If the vibration is occurred in a large-sized bus roof, it makes people annoying and complaining the quality of a large-sized bus. So in design stage, it must be considered. To assess vibration at the roof which is equipped with air conditioner in design stage, finite element model is constructed. Computer simulation analysis and experimental method are performed. The dynamic characteristics of the large-sized bus are found by using eigenvalue method. It is related with dynamic behavior. The running conditions of a large-sized bus are velocity and road condition which followed experimental conditions. And the frequency response of a large-sized bus is well correlated with analysis result. Modal participation method is used for finding major modes at each peak. Using this method, we found that front and rear suspension system, engine mounting system and roof structure are the major reasons of the roof vibration. To reduce vibration level of roof in a large-sized bus, spring stiffness of front and rear suspension system, spring stiffness of engine mounting system and roof structure are properly combined. From this study, the vibration characteristics of the roof structure of a large-sized bus can be to a satisfactory level.