摘要
对磁流变(MR)阻尼器进行了实索减振试验。试验时改变MR阻尼器的输入电压来改变MR阻尼器的输出力。通过人工激振拉索后,测得拉索的振动波腹点位移衰减时程曲线,计算得拉索的对数衰减率值。结果表明拉索的对数衰减率值与MR阻尼器的输入电压、拉索振动阶数和拉索振幅均相关。拉索的对数衰减率值当附加MR阻尼器有输入电压时有了大幅增长,其值在大部分振幅区域内大于0.03,可满足拉索减振要求;而当MR阻尼器无电压输入时对数衰减率值小于0.03,无法满足拉索减振要求。试验发现拉索的对数衰减率值-振幅曲线随着MR阻尼器的输入电压及振动模态阶数大小的变化具有良好的规律性,且针对各阶振型具有相接近的最大对数衰减率值和最小的对数衰减率值,提示了利用MR阻尼器进行半主动优化控制的可能性。
A full-scale cable vibration mitigation experiment is conducted using a 215.58 m long stay cable and a set of MR dampers.The cable is excited by human power and then the free decay curve is recorded.The logarithmic decrement of the cable is then calculated from the free decay curve of the displacement data.It is found that due to the strong nonlinear mechanical behaviors of MR damper,the logarithmic decrement of the cable with MR dampers varies with applied voltages on MR dampers,cable vibration mode and amplitude.The test results show that the damping of the cable increases greatly when the MR dampers are voltage strengthened.However,when the MR dampers are not voltage strengthened,the measured logarithmic decrement is smaller than 0.03.It is found that the tested damping versus amplitude curves are similar to each other,the maximum and minimum logarithmic decrement value are also very close to each other for modes 1 to 3,indicating a possibility of optimization using semi-active controlled MR damper.A simple theoretical design formulation of damping of cable with MR dampers is developed for engineering practice.
出处
《振动与冲击》
EI
CSCD
北大核心
2008年第6期92-95,102,共5页
Journal of Vibration and Shock
基金
深圳大学科研启动基金资助项目(200808)
国家自然科学基金面上基金资助项目(50678123)
国家高新技术研究发展专项(863计划)资助项目(2006AA11Z120)
关键词
实索试验
MR阻尼器
对数衰减率
电压
模态
振幅
full-scale cable test
MR damper
logarithmic decrement
voltage
modes
amplitude
