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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean Society for Noise and Vibration Engineering
Journal Basic Information
Journal DOI :
The Korean Society for Noise and Vibration Engineering
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Volume & Issues
Volume 23, Issue 12 - Dec 2013
Volume 23, Issue 11 - Nov 2013
Volume 23, Issue 10 - Oct 2013
Volume 23, Issue 9 - Sep 2013
Volume 23, Issue 8 - Aug 2013
Volume 23, Issue 7 - Jul 2013
Volume 23, Issue 6 - Jun 2013
Volume 23, Issue 5 - May 2013
Volume 23, Issue 4 - Apr 2013
Volume 23, Issue 3 - Mar 2013
Volume 23, Issue 2 - Feb 2013
Volume 23, Issue 1 - Jan 2013
Selecting the target year
A Study for High Speed Judder Evaluation on Brake System
Kim, Seonghwan ; Cho, Sungsun ; Lee, Junghwan ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 23, issue 6, 2013, Pages 485~494
DOI : 10.5050/KSNVE.2013.23.6.485
This paper deals with experimental evaluation methods for high speed judder on the brake-caliper system. Firstly, two types of brake caliper systems due to the wheel vibration was evaluated. Secondly, the high-speed judder of the brake was also investigated using the subjective rating evaluation in the high-speed road test. These experimental evaluations were carried out by changing the materials of brake pad and the specifications of the brake-corner module. Based upon the test results, a new specification of the brake pad,
vertical chamfer, was proposed. The new brake pad showed 3 points, 60 %, improvement in the subjective-rating evaluation comparing with conventional one. Besides, we need to decide properly with judder characteristic of pad material and have to carefully take into consideration other design parameters; caliper, disc, and the braking performance, durability, squeal noise.
An Experimental Study on the Noise and Vibration reduction of Projector Driving Board
Choi, Youngsoo ; Song, Keunyoung ; Yi, Jongkwon ; Oh, Honglyeol ; Lee, Seunggyu ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 23, issue 6, 2013, Pages 495~501
DOI : 10.5050/KSNVE.2013.23.6.495
This paper deals with noise reduction on a light source driving board in a projector. We analyze causes of noise/vibration in the circuit with the present increasing use of LD and LED driving boards. The main source of noise is the MLCC in the driving board. Our aim is to investigate how the mechanical arrangement of the circuit elements affects noise reduction. The result of our experiment shows that noise can be reduced by symmetrical arrangement and slots in PCB. This result is expected to facilitate a variety of applications for manufactures without a need to change circuit elements.
Numerical Analysis on the Flow Noise Characteristics of Savonius Wind Turbines
Kim, Sanghyeon ; Cheong, Cheolung ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 23, issue 6, 2013, Pages 502~511
DOI : 10.5050/KSNVE.2013.23.6.502
Noise performance of small wind turbines is critical since these are generally installed near the community. In this study, flow noise characteristics of Savonius wind turbines are numerically investigated. Flow field around the turbine are computed by solving unsteady RANS equation using CFD techniques and the radiated noise are predicted by applying acoustic analogy to the computed flow data. Parametric study is then carried out to investigate the effects of operating conditions and geometric design factors of the Savonius wind turbine. Tonal noise components with higher harmonic frequency than the BPF are identified in the predicted noise spectra from a Savonius wind turbine. The end-plates and helical blades are shown to reduce overall noise levels. These results can be used to design low-noise Savonius wind turbines.
Wave Propagation in a Strip Plate with Longitudinal Stiffeners
Kim, Hyungjun ; Ryue, Jungsoo ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 23, issue 6, 2013, Pages 512~519
DOI : 10.5050/KSNVE.2013.23.6.512
It is important to understand the vibrating behavior of plate structures for its many engineering applications. In this study, the vibration characteristics of strip plates that have finite width and infinite length are investigated theoretically and numerically. The waveguide finite element(WFE) approach, which is an effective tool for studying waveguide structures, is used in this study. The WFE method requires only a cross-sectional finite element model, and uses theoretical harmonic solutions to assess wave propagation along the longitudinal direction. First, WFE results for a simple strip plate are compared with the theoretical results(i.e., dispersion diagrams and point mobilities) to validate the numerical model. Then, in the numerical analysis, different numbers of longitudinal stiffeners are included in the plate model to investigate the effects of stiffeners in terms of the dispersion curves and mobilities. Finally, the dispersion curves of a stiffened double plate are obtained to examine the characteristics of its wave propagation.
A Study on the Vibration Reduction of an Automobile Fuel Pump
Kim, Byeong Jin ; Won, Hong In ; Lee, Seong Won ; Park, Sang Jun ; Chung, Jintai ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 23, issue 6, 2013, Pages 520~526
DOI : 10.5050/KSNVE.2013.23.6.520
This article presents the reduction of vibration generated by an automobile fuel pump. In order to analyze the vibration of the fuel pump, a simplified dynamic model is established, which is composed of a rigid rotor and a equivalent springs. The equivalent stiffnesses of the upper and lower assemblies are evaluated by the comparison of modal testing results and the finite element analysis. The stiffness for the oil film of the journal bearing is extracted by using Reynold`s equation. In addition, the time responses for the vibration of the fuel pump are computed by using a commercial multi-body dynamics software, RecurDyn. Based on these results, some design suggestions are proposed to reduce the vibration of an automobile fuel pump.
Prediction of a Structural Vibration and Radiated Noise of High-voltage Transformer through Force Identification
Yoo, Suk-Jin ; Jung, Byung-Kyoo ; Jeong, Weui-Bong ; Hong, Chinsuk ; Kim, Tae-Yong ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 23, issue 6, 2013, Pages 527~536
DOI : 10.5050/KSNVE.2013.23.6.527
In order to predict structural vibration and radiated noise of high-voltage transformer in operation, it is necessary to precisely find the excitation force generated by the coils and core. However, finding the excitation force through experiments of high voltage transformer in operation is not possible. Therefore, this paper deals with identifying the excitation force by using the acceleration data measured through experiments and the transfer function estimated through finite element model. A method to predict structural vibration and radiated noise was also proposed. Three-phase windings and the core are the source of high-voltage transformer. The excitation forces were identified using the acceleration data and the transfer function of the surface of the tank. Structural vibration and radiated noise from the surface of the tank was predicted by using the identified excitation force. As a result of the interpretation of the experimental and computational analysis of structural vibration from the surface of the tank and radiated noise from the field point, the interpretation of the computational analysis showed relatively good accordance with the experiment.
A Mathematical Approach for Modal Frequency Analysis in Actuators
Lee, Kyung Taek ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 23, issue 6, 2013, Pages 537~545
DOI : 10.5050/KSNVE.2013.23.6.537
In this paper, the vibration for actuators having lens module, confined to lateral and torsional directions of suspensions, is described by mathematically analyzing its suspension configuration and motion. In order to prove the accuracy of this result, it is compared to a finite element analysis. Also it is shown that modal frequencies can be modified by changing design parameters in mathematical motion expressions.
Mathematical Model for a Mode-sequence Reversed Two-degrees-of-freedom Piezoelectric Vibration Energy Harvester
Lee, Sowon ; Kim, Yoon Young ; Kim, Jae Eun ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 23, issue 6, 2013, Pages 546~552
DOI : 10.5050/KSNVE.2013.23.6.546
A cantilevered piezoelectric energy harvester(PEH) and an auxiliary mass-spring unit can be integrated into a novel two-degrees-of-freedom PEH where its lowest eigenmode is not an in-phase modes but an out-of-phase mode. This typical behavior was shown to enhance output power considerably compared with its stand-alone counterpart. The objective of this study is to newly develop a continuum-based mathematical model suitable for efficient analysis of the mode-sequence reversed PEH. Once such a mathematical model is available, various physical behaviors can be analytically investigated for better designs. After a new mathematical model is developed, its validity is checked by using ANSYS results, in terms of resonant frequency, open-circuit voltage, and output power with a specified external resistance.
Variability Analysis of Dynamic Characteristics in Rubber Engine Mounts Considering Temperature Variation
Hwang, In Seong ; Ahn, Tae Soo ; Lee, Dooho ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 23, issue 6, 2013, Pages 553~562
DOI : 10.5050/KSNVE.2013.23.6.553
Vehicle vibrations arise from engine and road surface excitations. The engine mount system of a passenger car sustains the engine weight and insulates the excitation force from the engine system. The dynamic properties of viscoelastic material used for the vehicle engine mounts have large variation due to environmental factors such as environmental temperature and humidity etc. The present study aims to investigate the variability of dynamic characteristics in rubber engine mounts considering both environmental temperature change and material model errors/uncertainty. The engine mounts for a passenger car were modeled using finite element method. Then, the dynamic stiffness variability of the engine mounts were estimated using Monte Carlo simulation method. In order to estimate the variations in the storage and loss moduli of the viscoelastic materials, the material properties of the synthetic rubber were expressed as a fractional-derivative model. Next, in order to simulate the uncertainty propagation of the dynamic stiffness for the engine mounts due to the storage and loss moduli variations, the Monte Carlo simulation was used. The Monte Carlo simulation results showed large variation of the engine-mount stiffness along frequency axis.
Error Characteristics of Ship Radiated Noise Estimation by Sea Surface Scattering Effect
Park, Kyu-Chil ; Park, Jihyun ; Seo, Chulwon ; Choi, Jae Yong ; Lee, Phil-Ho ; Yoon, Jong Rak ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 23, issue 6, 2013, Pages 563~573
DOI : 10.5050/KSNVE.2013.23.6.563
The ship radiated noise level fluctuates by the interference between direct and reflected paths. The effect of sea surface reflection path on interference depends strongly on sea surface roughness. This paper describes error characteristics of ship acoustic signature estimation by sea surface scattering effect. The coherent reflection coefficient which explains a magnitude of sea surface scattering and its resultant interference acoustic field is analyzed quantitatively as a function of a grazing angle, effective surface height, frequency, source-receiver range and depths of source and receiver. Theoretical interference acoustic field is compared with experimental result for two different sea surfaces and five different frequencies by changing source-receiver range. It is found that both matches well each other and a magnitude of interference acoustic field is decreasing by increasing a grazing angle, effective surface height, frequency, and depths of source and receiver and decreasing source-receiver range. For given experimental conditions, the transmission anomaly which is a bias error of ship acoustic signature estimation, is about a range of 1~3 dB. The bias error of an existing ship radiated noise measurement system is also analyzed considering wind speed, source depth and frequency.
Wave Transmission Analysis of Co-planar Coupled Semi-infinite Mindlin Plate
Park, Young-Ho ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 23, issue 6, 2013, Pages 574~580
DOI : 10.5050/KSNVE.2013.23.6.574
At high frequencies, the statistical approach such as statistical energy analysis(SEA) and energy flow analysis(EFA) has been applied for estimation of vibroacoustic responses of various built-up structures. The energy coupling relationship between finite coupled structures is required to estimate vibrational energetics of built-up structures. Mindlin plate theory includes the rotatory inertia and shear deformation effects which are dominant as frequency increases. In this paper, the wave transmission analysis is successfully performed for EFA of co-planar coupled Mindlin plates.