• Journal of KSNVE
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• v.10 no.1
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• pp.5-12
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• 2000

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.04a
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• pp.219-220
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• 2014

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.610-611
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• 2010

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.455-456
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• 2014

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.996-997
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• 2014

• Journal of KSNVE
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• v.6 no.4
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• pp.431-438
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• 1996

The channel type structure which has large openings is frail with respect to torsional strength, and the horizontal-torsional motion is highly coupled, because of the large difference between the centroil and the shear center. Also, a discontinuous boundary phase is came from tansition section between the opened section and the closed section. To analyze the Bending- Torsional coupled mode parameters for the channel type structure, the Transfer Matrix Method was used. Comparing the result of F.D.M.T.M.M yields good results in relatively low frequency region.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.393-399
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• 2008

A modeling method for the modal analysis of a pre-twisted multi-packet blade system undergoing rotational motion is presented in this paper. Blades are idealized as pre-twisted cantilever beams that are fixed to a rotating disc. The stiffness coupling effects between blades due to the flexibilities of the disc and the shroud are modeled with discrete springs. The coupling effect between chordwise and flapwise bending deflection is also considered. Hybrid deformation variables are employed to derive the equations of motion. To obtain more general information, the equations of motion are transformed into dimensionless forms in which dimensionless parameters are identified. The effects of the dimensionless parameters and the number of packets as well as blades on the modal characteristics of the rotating multi-packet pre-twisted blade system are investigated with some numerical examples.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.609-616
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• 2001

The vibrational characteristics of nonuniform circular rods have been studied theoretically and experimentally in this paper. The differential equation of torsional motion expressed in terms of the angular displacement has been solved exactly and approximately for a stepped circular rod and for a conically-tapered rod. Solutions of the boundary-value problem have yielded the natural frequencies, mode shapes and forced responses of the rods. The theoretical solutions of forced response have been verified by comparing them with experimental ones.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.9
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• pp.667-674
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• 2014

A ship's propulsion shafting system is subjected to varying magnitudes of intermittent loadings that pose great risks such as failure. Consequently, the dynamic characteristic of a propulsion shafting system must be designed to withstand the resonance that occurs during operation. This resonance results from hydrodynamic interaction between the propeller and fluid. For ice-class vessels, this interaction takes place between the propeller and ice. Producing load- and resonance-induced stresses, the propeller-ice interaction is the primary source of excitation, making it a major focus in the design requirements of propulsion shafting systems. This paper examines the transient torsional vibration response of the propulsion shafting system of an ice-class research vessel. The propulsion train is composed of an electric motor, flexible coupling, spherical gears, and a propeller configuration. In this paper, the theoretical analysis of transient torsional vibration and propeller-ice interaction loading is first discussed, followed by an explanation of the actual transient torsional vibration measurements. Measurement data for the analysis were compared with an applied estimation factor for the propulsion shafting design torque limit, and they were evaluated using an existing international standard. Addressing the transient torsional vibration of a propulsion shafting system with an electric motor, this paper also illustrates the influence of flexible coupling stiffness design on resulting resonance. Lastly, the paper concludes with a proposal to further study the existence of negative torque on a gear train and its overall effect on propulsion shafting systems.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.39 no.2
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• pp.118-123
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• 2002

A torque transmission system, which is composed of serveral gears and couplings, is flexible. Therefore, the torsion vibration occurs when the motor speed abruptly changes. Consequently, for accuracy characteristic response of motor, we must suppressed vibration. Therefore, vibration suppression is very important motor control. In order to suppress the vibration, various control method have been proposed. Specially, one method of vibration suppression is used disturbance observer and filter. The disturbance observer is used to suppress the vibration in this method. By feedback of the estimated torsion torque, the vibration can be suppressed. The coefficient diagram method is used to design the filter and proportional controller. But using coefficient diagram method, not adapted controller parameter in disturbance. In order to solve this problem. we used fuzzy controller for auto tuning controller parameter $K_P$. We proved of this approach is confirmed by simulation.