한국소음진동공학회:학술대회논문집 (Proceedings of the Korean Society for Noise and Vibration Engineering Conference)
- 한국소음진동공학회 2014년도 추계학술대회 논문집
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- Pages.402-403
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- 2014
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- 1598-2548(pISSN)
지지점 간극을 갖는 다점지지 관의 지지점 간극 크기에 따른 감쇠특성 비교
Loosely supported multi-span tube damping according to the support clearance
초록
Damping of multi-span tube with loose supports according to the finite support clearances is investigated through the experimental modal analysis. Loose intermediate support leads to strong nonlinearity in tube dynamics, provides statistical nature, and increases tube damping through impacting and friction at the supports. Fraction of critical damping was estimated by the modal curve fitting to parameter estimation from the measured frequency response functions. Magnitude of random excitation force, which can reproduce the in-situ excitation in operating environment, was maintained as constant value with a fine tolerance during vibration testing. Range of input force was carefully selected to cover from the low magnitude excitation for linearly behaved tube motion to high magnitude of force for nonlinearly-behaved tube motion. Estimated critical damping ratio shows scatters in data and tends to increase as the magnitude of rising force and decrease with upward frequency variation. Larger size of support gap increases multi-span tube damping for high magnitude of excitation.
키워드