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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 22, Issue 12 - Dec 2012
Volume 22, Issue 11 - Nov 2012
Volume 22, Issue 10 - Oct 2012
Volume 22, Issue 9 - Sep 2012
Volume 22, Issue 8 - Aug 2012
Volume 22, Issue 7 - Jul 2012
Volume 22, Issue 6 - Jun 2012
Volume 22, Issue 5 - May 2012
Volume 22, Issue 4 - Apr 2012
Volume 22, Issue 3 - Mar 2012
Volume 22, Issue 2 - Feb 2012
Volume 22, Issue 1 - Jan 2012
Selecting the target year
A Seismic Analysis for Driving Gear Reducer of ESW Traveling Sea Water Screen
Kim, Chang-Won ; Lee, Young-Shin ; Kim, Heung-Tae ; Kim, Jee-Won ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 7, 2012, Pages 599~604
DOI : 10.5050/KSNVE.2012.22.7.599
In this study, the safety of the driving gear reducer of ESW(essential service water) traveling sea water screen was evaluated through seismic analysis. Mode analysis of gear reducer was performed for reliability of analysis. Seismic analysis was performed in operating basis earthquake(OBE) and safe shutdown earthquake(SSE), which were applied as design condition using floor response spectrum( FRS). The maximum strain of gear reducer under OBE and SSE were 20.4
, respectively. The maximum stresses were 2.42 MPa under OBE condition and 4.36 MPa under SSE condition, which were smaller than the allowable strength of material.
Design of Decision Error Model for Reliability of Sound Quality Analysis and Its Experimental Verification
Kim, Eui-Youl ; Lee, Young-Jun ; Lee, Sang-Kwon ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 7, 2012, Pages 605~618
DOI : 10.5050/KSNVE.2012.22.7.605
In this study, the possibility of decision error is investigated to identify and improve the reliability of participants in the process of conducting the sound quality analysis for laser printers. So far, there is not a way to identify and express the possibility of individual participant quantitatively. Thus, the decision error model is proposed which is based on the expectation value between the perceived sounds. Through the experimental verification on the laser printers, it was found that the possibility of decision error is affected according to the normalized difference. The possibility of decision error has inversely proportional to the normalized difference between the perceived sounds. When the normalized difference becomes small value, the uncertainly between decisions is inversely increase, and then it is difficult to obtain the proper result in the process of the jury evaluation for laser printers. For this reason, in this study, the proposed decision error model is added in the previous step of the correlation verification. Comparing to the conventional process only using the correlation based method, after the reliability of each participant is verified, the correlation with the mean response of participants is verified. It was found that the participants who were recognized as having unusual preferences are actually identified as having the reliability problem. Based on the results of this study, the proposed decision error model will be helpful to identify and improve the reliability of participants in the following study for the sound quality analysis.
The Grid Strap Vibration Characteristics of the 5×5 Nuclear Fuel Mock-up
Kim, Kyoung-Hong ; Park, Nam-Gyu ; Kim, Kyoung-Ju ; Suh, Jung-Min ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 7, 2012, Pages 619~625
DOI : 10.5050/KSNVE.2012.22.7.619
Since the fuel is always exposed to turbulent flow, the grid strap shows flow induced vibration characteristics that impact on the nuclear fuel soundness. The dynamic behavior of grids in nuclear fuels is quite complex, since two pairs of spring and dimple support are contacted with rods by friction in the limited space. This paper focuses on investigation of the grid strap(test fuel strap, TFS) vibration in one cell. TFS consists of a single spring and double dimples. To identify the grid strap vibration, modal analysis of the strap is performed using finite element method(FEM). Modal testing on a
grid structure without rods is performed. The modal testing results are compared to analytic results. In addition, random test considering rod effect is performed about a
grid with rods under real contact condition in the air. Finally, the strap vibration of a
fuel bundle in investigation of flow induced vibration(INFINIT) facility is measured in real fluid velocity condition without heating. It is shown that modal frequencies from the test are almost equal to those peak frequencies in the INFINIT test.
Sound Pressure Sensitivity Variation of the Hollow Cylinder Type Sagnac Fiber Optic Sensor According to the Mandrel Install Direction and Its Material
Lee, Jong-Kil ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 7, 2012, Pages 626~633
DOI : 10.5050/KSNVE.2012.22.7.626
In this paper, sound pressure sensitivity of the fiber optic acoustic sensor according to sensor direction and mandrel material were investigated experimentally. Three different directions were selected as stand, lay, and hole. Hollow cylinder type mandrel dimension is 30 mm in outer diameter, 45 mm in length, and 2 mm in thickness, and about 50 m optical fibers were wounded on the surface of the mandrel. Non-directional sound speaker was used as a sound source. Sagnac interferometer and single mode fiber, a laser with 1,550 nm in wavelength,
coupler were used. Based on the experimental results, lay direction`s sensitivity is the highest in the frequency range of 2 kHz~4 kHz. `PTFE+carbon` material is more sensitive than PTFE in the frequency range of 5 kHz~20 kHz. Sound pressure detection sensitivity depends on the mandrel direction and material under certain frequency.
Development of Dynamic Modeling and Control Algorithm for Lateral Vibration HILS of Railway Vehicle
Lee, Jae-Ha ; Kwak, Moon-K. ; Yang, Dong-Ho ; You, Won-Hee ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 7, 2012, Pages 634~641
DOI : 10.5050/KSNVE.2012.22.7.634
This paper is concerned with the dynamic modeling for the hardware-in-the-loop simulation of lateral vibrations of a railway vehicle. The resulting dynamic model is a nine degree-of-freedom model which can describe the lateral, roll and yaw motions of the car body and two bogies. It is assumed that the external disturbances come from wheel motions. In order to test the efficacy of the model, the linear quadratic regulator and the sky-hook control algorithm were designed and applied to the model. The simulation results show that both control algorithms are effective in suppressing the vibrations of railway vehicles.
Unbalance Response Analysis of Copper Die Casting High Speed Induction Motor
Hong, Do-Kwan ; Jung, Seung-Wook ; Woo, Byung-Chul ; Koo, Dae-Hyun ; Ahn, Chan-Woo ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 7, 2012, Pages 642~649
DOI : 10.5050/KSNVE.2012.22.7.642
This paper deals with a copper die casting induction motor which has several advantages of motor performance. The developed motor is used as spindle motor in machining center. The dynamic characteristic analysis of rotor is dealt with for precision machining. The critical speed of rotor considering rotation and gyroscopic effect should be above operating speed, 18,000 rpm, and have a 201 % sufficient separation margin. Also, the 3-D unbalance vibration response analysis is performed and enabled the prediction of the expected vibration amplitude by unbalance in high speed. The unbalance vibration responses of each position on the rotor are satisfied with allowable vibration displacement of API 611 standard according to balancing G grade(G 0.4, G 2.5, G 6.3). Copper die casting high speed induction motor is successfully developed and verified by experiment.
Robust Near Time-optimal Controller Design for a Driving System Using Lyapunov Stability
Lee, Seong-Woo ; Song, Oh-Seop ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 7, 2012, Pages 650~658
DOI : 10.5050/KSNVE.2012.22.7.650
This paper proposes a high performance position controller for a driving system using a time optimal controller which has been widely used to control driving systems to achieve desired reference position or velocity in a minimum response time. The main purpose of this research lies in an improvement of transient response performance rather than that of steady-state response in comparison with other control strategies. In order to refine the scheme of time optimal control, Lyapunov stability proofs are incorporated in a controller of standard second order system model. This scheme is applied to the control of a driving system. In view of the simulation and experiment results, the standard second order system model exhibits better minimum-time control performance and robustness than double integral system model does.
Dynamic Characteristic of Coupled Pre-twist Blade and Shaft System
Lee, Hwan-Hee ; Song, Ji-Seok ; Na, Sung-Soo ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 7, 2012, Pages 659~666
DOI : 10.5050/KSNVE.2012.22.7.659
A nonlinear dynamic model for the shaft-disk-blade unit is developed in this study. In this regard, the rotating flexible blade, with a pre-twist angle, attached to a rigid disk driven by a shaft which is flexible in torsion is developed. The rotor-blade coupled model is derived using Lagrange equation in conjunction with the assumed mode method to discretize the blade deformation. The equations of motion are analyzed based on the small deformation theory for the blade and shaft torsional deformation to obtain the system natural frequencies for various system parameters.
Damage Estimation Method for Monopile Support Structure of Offshore Wind Turbine
Kim, Sang-Ryul ; Lee, Jong-Won ; Kim, Bong-Ki ; Lee, Jun-Shin ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 7, 2012, Pages 667~675
DOI : 10.5050/KSNVE.2012.22.7.667
A damage estimation method for support structure of offshore wind turbine using modal parameters is presented for effective structural health monitoring. Natural frequencies and mode shapes for a support structure with monopile of an offshore wind turbine were calculated considering soil condition and added mass. A neural network was learned based on training patterns generated by the changes of natural frequency and mode shape due to various damages. Natural frequencies and mode shapes for 10 prospective damage cases were input to the trained neural network for damage estimation. The identified damage locations and severities agreed reasonably well with the accurate damages. Multi-damage cases could also be successfully estimated. Enhancement of estimation result using another parameters as input to neural network will be carried out by further study. Proposed method could be applied to other type of support structure of offshore wind turbine for structural health monitoring.
Numerical Analysis of Heavy-weight Impact Noise for Apartment Units Considering Acoustic Mode
Mun, Dae-Ho ; Park, Hong-Gun ; Hwang, Jae-Seung ; Hong, Geon-Ho ; Im, Ju-Hyeuk ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 7, 2012, Pages 676~684
DOI : 10.5050/KSNVE.2012.22.7.676
Numerical analysis was performed to investigate the heavy-weight impact noise of apartment houses. The FEM is practical method for prediction of low-frequency indoor noise. The results of numerical analysis, the shape of the acoustic modes in room-2 are similar to that of acoustic pressure field at the fundamental frequency of acoustic modes. And the acoustic pressure was amplified at the natural frequency of the acoustic modes and structural modes. The numerical analysis result of sound pressure level at 63 Hz and 125 Hz octave-band center frequency are similar to the test results, but at 250 Hz and 500 Hz have some errors. Considering most of bang-machine force spectrum exists below 100 Hz, the noise at 250 Hz and 500 Hz are not important for heavy-weight impact noise. Thus, the FEM numerical analysis method for heavy-weight impact noise can apply to estimate heavy-weight impact noise for various building systems.
Development of Internal Inflow/outflow Steady Mean Flow Boundary Condition Using Perfectly Matched Layer for the Prediction of Turbulence-cascade Interaction Noise
Kim, Dae-Hwan ; Cheong, Cheol-Ung ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 7, 2012, Pages 685~691
DOI : 10.5050/KSNVE.2012.22.7.685
It is essential for the accurate time-domain prediction of broadband noise due to turbulence-cascade interaction to develop inflow/outflow boundary conditions to satisfy the following three requirements: to maintain the back ground mean flow, to nonreflect the outgoing disturbances and to generate the specified input gust. The preceding study showed that perfectly matched layer(PML) boundary condition was successfully applied to absorb the outgoing disturbances and to generate the specified gust in the time-domain computations of broadband noise due to interaction of incident gust with a cascade of flat-plates. In present study, PML boundary condition is extended in order to predict steady mean flow that is needed for the computation of noise due to interaction of incident gust with a cascade of airfoils. PML boundary condition is originally designed to absorb flow disturbances superimposed on the steady meanflow in the buffer zone. However, the steady meanflow must be computed before PML boundary condition is applied on the flow computation. In the present paper, PML equations are extended by introducing source term to maintain desired mean flow conditions. The extended boundary condition is applied to the benchmark problem where the meanflow around a cascade of airfoils is predicted. These illustrative computations reveal that the extended PML equations can effectively provide and maintain the target meanflow.
Improved Transmission Path Visualization of Vibration Power Flow for Stiffened Plate Using Streamlines Representation
Fawazi, Noor ; Jeong, Un-Chang ; Oh, Jae-Eung ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 7, 2012, Pages 692~700
DOI : 10.5050/KSNVE.2012.22.7.692
Vibration intensity has been used to localize vibration source of a vibrating system. Not only that, vibration intensity has also been used for structural diagnostic in identifying crack and mounted stiffeners. To clearly identify the location of vibration source and understand the changes of energy transmission path, clear flow visualization is required. Most of previous works used vectors to indicate the magnitude and direction of emerging vibration energy and transmission paths. However, due to the large surface area of a plate like-structure, clear transmission paths cannot be achieved using vector visualization. This becomes an issue when detail vector flow at all locations of the whole plate surface is required. In this study, streamlines visualization is used to clearly indicate the power flow transmission path at all plate surface. By using streamlines representation, not only clear transmission paths are obtained, but also improves the vector visualization which helps us to understand the changes of the energy flow especially for stiffened plates. In this study, vibration intensity computation is firstly compared to previous work to validate the vibration intensity computation. To clearly show the power flow transmission paths, streamlines representation is shown. This representation overcomes the unclear vector direction especially for stiffened plates. Different pattern of energy transmission path can be observed using streamlines representation for stiffened and unstiffened plate. The complex streamlines pattern can also be observed at high resonance frequencies which is unclear by using vector representation.