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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 13, Issue 12 - Dec 2003
Volume 13, Issue 11 - Nov 2003
Volume 13, Issue 10 - Oct 2003
Volume 13, Issue 9 - Sep 2003
Volume 13, Issue 8 - Aug 2003
Volume 13, Issue 7 - Jul 2003
Volume 13, Issue 6 - Jun 2003
Volume 13, Issue 5 - May 2003
Volume 13, Issue 4 - Apr 2003
Volume 13, Issue 3 - Mar 2003
Volume 13, Issue 2 - Feb 2003
Volume 13, Issue 1 - Jan 2003
Selecting the target year
Assessment of Vibration Transmissibility for Prediction of Heavy Floor Impact Sound
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 6, 2003, Pages 415~422
DOI : 10.5050/KSNVN.2003.13.6.415
In an apartment buildings, the floor Impact sound from upstairs has been regarded as a main source of noise causing discontentment among occupants. To set the optimum design for sound insulation, it is necessary to suggest the useful tools or technique that predict the floor impact sound. The purpose of this study is to suggest the supplementary formula(equation) and constant k considering vibration transmissibility in order to predict more precisely heavy floor impact sound by Impedance Method that have been briskly studied in Japan from comparing the measured values with the predicted values. The analyzed results had showed that if the damping material was glass wool or rubber, k=5 was proper and if the damping material was polystyrene foam, k>5 was desirable.
Optimal Ply Design of Laminated Composite Plate with a Hole Considering Vibration
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 6, 2003, Pages 423~429
DOI : 10.5050/KSNVN.2003.13.6.423
On this study. we improved the efficiency applying algorithm that is repeatedly using table of orthogonal array in discrete design space and filling a defect of gradient method in continuous design space. we showed optimal ply angle that maximized 1st natural frequency of CFRP laminated composite plate without a hole and with a hole by each aspect ratio. In the case of CFRP laminated composite plate without a hole, we confirmed the reliance and efficiency of algorithm in comparison with the result of optimization achievement repeatedly using statistical table of orthogonal array of experimental design and the BFGS optimal design method.
Influence of Moving Masses on Dynamic Behavior of Cantilever Pipe Subjected to Uniformly Distributed Tangential Follower Forces
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 6, 2003, Pages 430~437
DOI : 10.5050/KSNVN.2003.13.6.430
A conveying fluid cantilever pipe subjected to a uniformly distributed tangential follower force and three moving masses upon it constitute this vibrational system. The influences of the velocities of moving masses, the distance between two moving masses, and the uniformly distributed tangential follower force have been studied on the dynamic behavior of a cantilever pipe system by numerical method. The uniformly distributed tangential follower force is considered within its critical value of a cantilever pipe without moving masses, and three constant velocities and three constant distances between two moving masses are also chosen. When the moving masses exist on pipe, as the velocity of the moving mass and the distributed tangential follower force Increases. the deflection of cantilever pipe conveying fluid is decreased, respectively Increasing of the velocity of fluid flow makes the amplitude of a cantilever pipe conveying fluid decrease. After the moving mass passed upon the pipe, the tip- displacement of a pipe is influenced by the coupling effect between interval and velocity of moving mass and the potential energy change of a cantilever pipe. Increasing of the moving mass make the frequency of the cantilever pipe conveying fluid decrease.
Measurement of Oblique Incidence Reflection Coefficient Using Beamforming Method
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 6, 2003, Pages 438~444
DOI : 10.5050/KSNVN.2003.13.6.438
A method using beamforming algorithm has been developed to measure oblique incidence reflection coefficients of sound absorption materials. MUSIC(multiple signal classification) method detects the angles of incidence and reflection. By separating the incident and reflected waves using beamforming method, the reflection coefficient is calculated. Spatial smoothing technique Is also used to reduce the coherence between the incident and reflected waves. Numerical and experiment results are performed to verify the accuracy of proposed method.
Booming Index Development of Interior Sound Quality on a Passenger Car Using Artificial Neural Network
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 6, 2003, Pages 445~451
DOI : 10.5050/KSNVN.2003.13.6.445
Booming sound is one of the most important interior sound of a passenger car. The conventional booming noise research was focused on the reduction of the A-weighted sound pressure level. However A-weighted sound pressure level cannot give the whole story about the booming sound of a passenger car. In this paper, we employed sound metrics, which are the subjective parameters, used in psycoacoustics. According to recent research results. the relation between sound metrics and subjective evaluation is very complex and has nonlinear characteristics. In order to estimate this nonlinear relationship, artificial neural network theory has been applied to derivation of sound quality index for booming sound of a passenger car.
Characteristics of Flow-induced Vibration for KSNP Steam Generator Tube at Concentrated Tube Plugging Zone
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 6, 2003, Pages 452~459
DOI : 10.5050/KSNVN.2003.13.6.452
The characteristics of fluid-elastic instability and effects of turbulent excitations for the KSNP steam generator tubes were investigated numerically. The information for the thermal-hydraulic data of the steam generator has been obtained by using the ATHOS3-MOD1 code and the flow-induced vibration(FIV) analysis has been conducted by using the PIAT(program for Integrity assessment of SG tube) code. The KSNP steam generator has the concentrated plugging zone at the vicinity of the stay cylinder inside the SG. To investigate the cause of the concentrated tube plugging zone, the FIV analysis has been performed for various column and row number of the steam generator tubes. From the results of FIV analysis the stability ratio due to the fluid-elastic instability and vibrational amplitude due to the turbulent excitation in the concentrated plugged zone have a trend of larger values than those of the outer concentrated tube Plugging zone.
A Study on the Identification of Aeroacoustic Noise and Noise Reduction for a Vacuum Cleaner
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 6, 2003, Pages 460~466
DOI : 10.5050/KSNVN.2003.13.6.460
The aeroacoustic characteristics and noise reduction method of a centrifugal fan for a bagless vacuum cleaner were studied. The major noise source of vacuum cleaner is the centrifugal fan. The impeller of the fan rotates over 30000 rpm and generates very high-level piercing noise. It was found that the dominant noise source of the fan is generated from the aerodynamic interaction between the highly rotating impeller and stationary diffuser. In order to reduce the high tonal sound generated from the aerodynamic interaction between the impeller and diffuser, tapered impeller was carefully designed and tested. The trailing edge of the tapered impeller was inclined and this reduces the flow interactions between the rotating impeller and the stationary diffuser because of some phase shift. The static efficiency of the new impeller is slightly lower than the conventional one. The overall SPL is reduced about 3.6 dBA. The SPL of blade passing frequency(BPF) is reduced about 6 dBA and the
BPF is reduced about 20 dBA. The vacuum cleaner with the tapered impeller has lower noise level than that of the previous impeller and the strong tonal sound was dramatically reduced.
Study on the Characteristics of the Upper Pad Fluttering in a 6-Pad, LOP Type, Tilting Pad Journal Bearing
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 6, 2003, Pages 467~473
DOI : 10.5050/KSNVN.2003.13.6.467
This paper describes the fluttering characteristics of the upper pad in a tilting pad journal bearing(6-pad, LOP type) using a steam turbine. In order to investigate the phenomena of the upper pad fluttering experimentally, the absolute vibration of the upper pads, the relative vibration between bearing and shaft and the circumferential distribution of the film thickness are measured under the different values of supply oil flow rate, shaft speed and bearing load. It can be known that the fluttering mechanism of the upper pads has a tendency of the self-excited vibration from the study of fluttering frequencies and amplitudes with the change of shaft speed. Furthermore, it is observed that the incipient upper pad fluttering velocity is increased by the increase of oil supply flow rate and the fluttering amplitude of the upper pads is increased by the decrease of the ell flow rate and by the increase of the bearing load.
A Modeling and Contact Force Analysis of the Catenary-pantograph System for a High-speed Rail Vehicle
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 6, 2003, Pages 474~483
DOI : 10.5050/KSNVN.2003.13.6.474
In this study, the dynamic characteristics of a catenary system and pantograph supplying electrical power to high-speed trains are investigated. One of the most important issues accompanied by increasing the speed of high-speed rail is stabilization of current collection. To stabilize current collection, it is necessary the contact force between the catenary and the pantograph to be kept continuous without loss of contact. The analytical model of a catenary and a pantograph is constructed to simulate the behavior of an actual system. The analysis of the catenary based on the Finite Element Method (FEM) is performed to develop a catenary model suitable for high speed operation. The reliability of the models is verified by the comparison of the excitation test with Fast Fourier Transform (FFT) data of the actual system. The static deflection of the catenary, stiffness variation in contact lines, dynamic response of the catenary undergoing constant moving load, contact force, and each state of the pantograph model were calculated. It is confirmed that a catenary and pantograph model are necessary for studying the dynamic behavior of the pantograph system.
Controllable Squeeze Film Damper Using an Electromagnet
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 6, 2003, Pages 484~489
DOI : 10.5050/KSNVN.2003.13.6.484
The paper represents stability of a rotor system with the squeeze film damper (SFD) using an electromagnet. The electromagnet is installed in the inner damper of the SFD. The proposed SFD has basically the property of a conventional SFD and variable damping property according to variation of the applied electric current. Therefore, when the applied current Is controlled, the whirling vibration of the rotor system can be effectively reduced in a wide operational speed range. In the present work, the performance of the SFD was experimentally investigated according to changing the magnetic field strength. As the applied current increased, damping ratios increased, while whirling amplitudes greatly reduced.
Dynamic Properties of Squeeze Type Mount Using MR Fluid
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 6, 2003, Pages 490~495
DOI : 10.5050/KSNVN.2003.13.6.490
This paper presents investigation of damping characteristics of squeeze mode type MR (magneto-rheological) mount experimentally. Since damping property of the MR fluid is changed by variation of the applied magnetic field strength, squeeze mode type MR mount proposed in the study has variable damping characteristics according to the applied magnetic field strength. In the present work, the performance of the mount was experimentally Investigated according to the magnetic field strength and exciting frequencies. The experimental results present that the MR mount can effectively reduce the vibration in a wide range of frequency by controlling the applied electromagnetic field strength. Viscous damping and stiffness coefficients of the MR mount tend to be changed according to the variation of the applied currents in this study and MR effect is reduced by increasing exciting frequency.