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Lee, Chan-Hui;Kim, Heu-Won
- Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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- 2012.04a
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- pp.686-690
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- 2012
The modal test has been carried out using the exciter machine to investigate the vibration characteristics of the hull and super structure of the ship. The conventional exciter acts only one(1) direction and the exciter should be reinstalled for different direction test, which consumes additional expense. The 3 axes exciter has been designed of which force acts three directions without reinstallation for efficient modal test of the ship. It consists of rotatable base frame structure and the clutch mechanism for the unbalances to excite three directions. And the 3 axes exciter for the local structure has been made in advance and its performance test was carried out in the laboratory. The developed 3 axes exciter shows the ability of three-directions excitation with simple operation and modal test for the various local structure of the ship will be performed.
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Yang, Chul-Ho
- Transactions of the Korean Society for Noise and Vibration Engineering
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- v.16 no.3 s.108
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- pp.233-239
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- 2006
The effect of the joint condition of automotive muffler shell and baffle on radiated noise from muffler shell Is studied. Shell vibration characteristics, especially shift In natural frequency and change in of response amplitude, was identified from finite element analysis and modal tests for various joint conditions between shell and baffle. When there is heat expansion and inner pressure from the exhaust 9as in the muffler with elliptical cross section, the shell expands out, and construct gap with baffles. This gap causes more degrees of freedom of shell vibration and natural frequency shift. By welding the muffler shell to the baffles or using a dual shell muffler, the radiated noise problem could be mitigated supplying more a rigid joint and damping, respectively.
https://doi.org/10.5050/KSNVN.2006.16.3.233 인용 PDF KSCI

이영섭;염병용;김진형;김명섭
- Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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- 2001.11a
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- pp.354-359
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- 2001
A flexible rotor was smoothly passed through its bending critical speed, which is supported by AFB. Then, maximum magnitude of the rotor vibration at the middle point was 25${\mu}$m. The test rig was largely consisted of air turbine, multi-leaf type air foil bearing and flexible rotor and its bending critical speed was 32,600 rpm. And the balancing system and method for field balancing of the flexible rotor were developd successfully.
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