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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
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
Dynamic Analysis of the Contact-free Surface Actuator
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 9, 2003, Pages 663~670
DOI : 10.5050/KSNVN.2003.13.9.663
As the micro-technologies in the high precision manufacturing processes are developed, the demand for micro actuating device is increasing. But, it is difficult to achieve high resolution and wide operating range simultaneously with the conventional actuating systems which are contacting and type of dual servo system. So, the contact-free surface actuators whose movers are suspended or levitated were proposed. These systems can be applied to high precision stages and alignment apparatuses. The suspended mover can be assumed to be rigid body, but the mover is a structure in this study, therefore the vibration caused during the operating process has a serious adverse effect on the performance and it is very important to identify the vibrational characteristics. In this paper, a contact-free surface actuator is modeled in finite element method and updated by using the experimental modal data. Finally, the static and dynamic characteristics of the finite element model are predicted and then discussed.
Vibration Phenomenon with Weight Change of 6 Bundle Boltless Spacer Damper
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 9, 2003, Pages 671~678
DOI : 10.5050/KSNVN.2003.13.9.671
Spacer dampers maintain the constant gaps between each conductor in a bundle conductor-transmission line, and are installed at proper intervals to keep a line from all sorts of damages derived from the vibration energy caused by mechanical or electrical external factors. It is most important to embody a technology which considers difficulties of maintenance and repair, and has optimum elements in order to prevent accidents such as destruction by fire or the snapping of a wire by the effect of vibration phenomenon coming from transmission line. In the present thesis, therefore, the analysis of vibratory characteristics of spacer damper is set up by analytical methods such as the analysis of conductor motion`s governing equation, the equation of spacer damper`s motion, spacer damper-fastened wire`s motion in a span, and the numerical analysis of finite difference method. Furthermore, the installation distance between spacer dampers was scrutinized by simulations of various vibration phenomena which change at any time as actual conditions do, and hereafter we will be able to analyze all kinds of vibration phenomena coming from a boltless spacer damper with 6 bundle conductor for 765 k V transmission line based on new analytical methods.
ER Smart Structures for Shock Wave Reduction
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 9, 2003, Pages 679~687
DOI : 10.5050/KSNVN.2003.13.9.679
Shock wave reduction in electrorheological(ER) smart structures is studied. ER insert is a composite structure comprising two elastic outer layers between which is sandwiched layer of ER fluid. When a voltage is applied across the outer layers. the shear modulus and the loss factor of the ER fluid are enabled, and thus the dynamic properties of the composite structure is altered. For the shock wave reduction in a hull mount of a submerged structure, ER inserts are made on the hull mount structure. To investigate the ER insert shape. many types of ER insert pattern are considered. Modal test of ER insert structures is performed to obtain the mode shapes, natural frequencies and the acceleration transmissibility. The acceleration transmissibility is reduced at such a frequency region when an electric field is applied. It is observed that the natural frequencies and mode shapes can be tunable by applying electric field. The ER-inserted hull mount is installed in an integrated system and the overall performance of shock wave reduction is tested. The possibility of shock wave reduction in the hull mount is demonstrated.
Nonlinear Dynamic Characteristics of Gear Driving System with Tooth Modification
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 9, 2003, Pages 688~693
DOI : 10.5050/KSNVN.2003.13.9.688
To reduce the vibration of a gear driving system. the modification of gear tooth from the orignal involute gear profile is usually done in gear manufacturers. The quantity of tooth modification has been decided on the basis of the interference between two gear teeth during gear meshing and the elastic deformation due to loading. However. the dynamic characteristics with tooth modification has to be investigated to avoid the instability to the variation of gear meshing stiffness and the nonlinearity due to gear backlash which results in sub- or super-harmonics in its responses. This research shows the dynamic characteristics with various tooth modifications in its type and quantity.
Experimental and Analytical Study of a Cooling Mechanism Using Acoustic Streaming by Ultrasonic Vibrations
Loh, Byoung-Gook ; Lee, Dong-Ryul ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 9, 2003, Pages 694~702
DOI : 10.5050/KSNVN.2003.13.9.694
A cooling mechanism using acoustic streaming by ultrasonic vibrations and associated convective heat transfer enhancement is investigated experimentally and analytically. Acoustic streaming pattern and associated heat transfer characteristics are presented. Analytical transient temperature profile of the heated plate following Nyborgs theory is accomplished along with experimental measurement. A temperature drop of 30 C is obtained in 4 minutes with vibration amplitude of 10
. As the vibration amplitude is further increased to 25
a temperature drop of 40 C is achieved that is the maximum temperature drop obtained with the current experimental apparatus. Analytical heat transfer solutions verified a temperature drop of 4
with a vibration amplitude of 25
at 28.4 kHz which is experimentally obtained.
A Fuzzy Expert System Based on Hybrid Database for Fault Diagnosis of Industrial Turbomachinery
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 9, 2003, Pages 703~712
DOI : 10.5050/KSNVN.2003.13.9.703
This paper suggests a fuzzy expert system for fault diagnosis of rotating machinery, based on modulated databases. In the proposed system, alarm and trip levels are set based on ISO, considering operating condition, machinery type and maintenance history. Input signals for diagnosis, such as sub-and super-harmonic components of vibration and mean value, are normalized from 0 to 1 under the threshold level and otherwise equal to one so that chronic faults slightly below the threshold level can be monitored. The database for diagnosis consists of two modules: the well-known Sohre`s chart module and if-then type rules. The Sohre`s chart is utilized for the most common problems of high-speed turbomachinery, while the rule-based module, which was collected from many papers and reports, is for diagnosing peculiar faults according to the type of machinery. To infer the results from two modules, a fuzzy operation of Yager sum was adopted. Using a simulator constructed in laboratory, experimental verification was performed for the cases of unbalance and resonance which were intended. The experimental results show that the proposed fuzzy expert system has feasibility in practical diagnosis of rotating machinery.
Experimental Investigation of the Response Characteristics of Korean -seated Subjects under Vertical Vibration: (II) Mechanical Impedances
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 9, 2003, Pages 713~719
DOI : 10.5050/KSNVN.2003.13.9.713
This paper introduces attempts to obtain the ‘representative’ characteristics of the mechanical impedance of seated Korean subjects under vertical vibration. Individual responses of driving-point mechanical impedance obtained from forty one Korean subjects are illustrated. Four kinds of vibration levels and three different sitting postures are selected to collect the responses of each subject. Those individual responses are used to estimate the ‘mean’ mechanical impedance, which may be expected to be a representative model to Korean subjects. Several interesting features of the estimated mechanical impedance are suggested and compared to those of ISO/DIS 5982.
Influence of Crack on Dynamic Behavior of Simply Supported Beam with Moving Mass
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 9, 2003, Pages 720~729
DOI : 10.5050/KSNVN.2003.13.9.720
An iterative modal analysis approach is developed to determine the effect of transverse open cracks on the dynamic behavior of simply supported Euler-Bernoulli beam with the moving mass. The influences of the depth and the position of the crack in the beam have been studied on the dynamic behavior of the simply supported beam system by numerical method. The crack section is represented by a local flexibility matrix connecting two undamaged beam segments i.e. the crack is modelled as a rotational spring. This flexibility matrix defines the relationship between the displacements and forces across the crack section and is derived by applying fundamental fracture mechanics theory. As the depth of the crack is increased the frequency of the simply supported beam with the moving mass is increased.
Investigation and Analysis of Regulations for the Safety of the Noise Barrier
Transactions of the Korean Society for Noise and Vibration Engineering, volume 13, issue 9, 2003, Pages 730~734
DOI : 10.5050/KSNVN.2003.13.9.730
For the noise reduction measures in a construction field or near the traffic line receiver is often the most economic measure in order to exclude the propagated sound. The dimension of the barrier is decided by the noise and construction design, and the constructive quality of a soundproof panel shall be secured in accordance with KS F4770 to guarantee the safety of sound barriers. In this paper the problems included in the KS F4770-1 that is the regulation for the metallic sound barrier of the absorption type are identified and it is suggested what to be corrected or improved. Through a series of the analyses, conclusions were reached that it is required to improve test methods in KS F4770-1 as well as to break down test loads for building more cost-effective sound barrier.