噪声与振动控制
譟聲與振動控製
조성여진동공제
Noise and Vibration Control
2015年
5期
189-192
,共4页
邹琳%胡勇%王汉封%汪秒%徐汉斌
鄒琳%鬍勇%王漢封%汪秒%徐漢斌
추림%호용%왕한봉%왕초%서한빈
振动与波%波浪型斜拉索%涡激振动%阻尼比%抑振%实验研究
振動與波%波浪型斜拉索%渦激振動%阻尼比%抑振%實驗研究
진동여파%파랑형사랍색%와격진동%조니비%억진%실험연구
vibration and wave%wavy stay cable%vortex-induced vibration%damping ratio%vibration suppression%experiment
针对目前改变斜拉索表面形状来抑制斜拉索由风载荷引起的振动所遇到的问题，采用热线风速仪、激光位移器测量和烟线等实验方法，实验研究在Re=6800～20480区域内波浪型斜拉索涡致耦合振动及频率“锁定”现象，并引入直斜拉索作为对比。实验表明：在相同的质量比和阻尼比下，波浪型斜拉索λ/D=2和λ/D=6同直斜拉索同样容易被诱导振动，波浪型λ/D=2比波浪型λ/D=6的减震效果要好，和直斜拉索相比，波浪型λ/D=2的诱导振动时最大振幅减小10%，锁定区间变短，主要是由于随着表面凹凸变化倾斜度较大，波浪型斜拉索表面的展向二次涡强度得以增强，一旦诱导振动，将干扰斜拉索的涡旋激励，从而达到减震的目的。
針對目前改變斜拉索錶麵形狀來抑製斜拉索由風載荷引起的振動所遇到的問題，採用熱線風速儀、激光位移器測量和煙線等實驗方法，實驗研究在Re=6800～20480區域內波浪型斜拉索渦緻耦閤振動及頻率“鎖定”現象，併引入直斜拉索作為對比。實驗錶明：在相同的質量比和阻尼比下，波浪型斜拉索λ/D=2和λ/D=6同直斜拉索同樣容易被誘導振動，波浪型λ/D=2比波浪型λ/D=6的減震效果要好，和直斜拉索相比，波浪型λ/D=2的誘導振動時最大振幅減小10%，鎖定區間變短，主要是由于隨著錶麵凹凸變化傾斜度較大，波浪型斜拉索錶麵的展嚮二次渦彊度得以增彊，一旦誘導振動，將榦擾斜拉索的渦鏇激勵，從而達到減震的目的。
침대목전개변사랍색표면형상래억제사랍색유풍재하인기적진동소우도적문제，채용열선풍속의、격광위이기측량화연선등실험방법，실험연구재Re=6800～20480구역내파랑형사랍색와치우합진동급빈솔“쇄정”현상，병인입직사랍색작위대비。실험표명：재상동적질량비화조니비하，파랑형사랍색λ/D=2화λ/D=6동직사랍색동양용역피유도진동，파랑형λ/D=2비파랑형λ/D=6적감진효과요호，화직사랍색상비，파랑형λ/D=2적유도진동시최대진폭감소10%，쇄정구간변단，주요시유우수착표면요철변화경사도교대，파랑형사랍색표면적전향이차와강도득이증강，일단유도진동，장간우사랍색적와선격려，종이체도감진적목적。
Considering the existing challenges in wind-induced vibration control of flexible stay-cables, a new modified wavy stay-cable was proposed to suppress the vibration and reduce the cable drag. By using hot-wire anemometer, laser displacement sensor, pressure scanning valve, smoke wire and some other experimental methods, the vortex-induced vibration (VIV) and the frequency lock-in phenomenon of the wavy stay cables at Re=6800-20480 were studied. The results were compared with those of the regular stay cable. The experimental results indicated that similar to the straight stay cable, the wavy stay cable with λ/D=2 and λ/D=6 can be induced the vibration easily at the same mass ratio and damping ratio. However, the vibration suppression effect of the wavy stay cables still exists. The vibration suppression effect of the wavy stay cable withλ/D=2 is better than that of the wavy stay cable with λ/D=6 . Compared with the straight stay cable, the maximum amplitude of the vortex-induced vibration can be reduced by 10%for the wavy-stay-cable, and the lock-in region is shortened. One of the main reasons is that the large variation of the modified wavy stay-cable surface can enhance the secondary spanwise vortex. Once the vortex vibration is induced, the large variation of the modified wavy stay-cable surface will interfere the vortex excitation so that the vortex shedding is controlled and the lift fluctuation is suppressed.
