摘要
运用福斯(Foss)迭代法求解设置黏性剪切阻尼器(VSD)减振拉索的振动方程,得到复特征值和对数衰减率。以对数衰减率大于等于0.03为目标函数,对杭州湾跨海大桥北航道桥斜拉索减振用VSD进行优化设计,并对安装VSD的减振效果进行分析。结果表明:减振拉索的每阶模态均有对应的VSD最优插板面积,高阶模态的最优插板面积小于低阶模态,高阶模态的对数衰减率受插板面积的影响比低阶模态大;在不考虑其他因素条件下插板面积大于150cm2时便可有效抑制斜拉索的各种风致振动;高阶模态的最大对数衰减率所对应的温度高于低模态最大对数衰减率所对应的温度,低温时低阶模态的对数衰减率大于高阶模态的对数衰减率,温度较高时高阶模态的对数衰减率大于低阶模态的对数衰减率。杭州湾跨海大桥北航道桥斜拉索安装VSD后,对数衰减率从0.015～0.0196提高到0.03～0.11,有效地减小了斜拉索的各种风致振动,达到了减振效果及设计目标。
Using a Foss iterative method, a fundamental function was solved for cable-damp vibration, and then the complex eigenvalues and logarithmic decrement ratios were obtained. Setting an objective function as a logarithmic decrement ratio equal or greater than 0.03, the parameters were optimized for a viscous shearing damper （VSD） installed on the northern waterway bridge of Hangzhou Bay sea-crossing bridge. Based on parameter optimization, the effect for the vibration suppression was analyzed after the installation of VSD on the Bridge. From the analysis of experimental data, it can be noted that the logarithmic decrement ratio is changed with the location of VSD installed. It is also shown that one reasonable value of an inserted plank in area can be gained in each mode of iteration. Under no consideration of other factors, the wind-induced vibration of cables can be effectively suppressed, if the area of inserted planks for VSD is greater than 150 cm 2. Considering the effect of temperature, it is noted that the ratio comes to be greater with temperature gradually increasing to the maximum. However, the ratio is decreased after the temperature reaches the maximum. In the test of VSD installed on various cables of the bridge, the logarithmic decrement ratio increased from 0.015～0.019 6 to 0.03～0.11. The conclusion can thus be drawn that the VSD can effectively reduce the cable vibration, which can achieve the damping effect and the design goal.
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2010年第2期45-49,共5页
China Railway Science
基金
国家自然科学基金资助项目(50778077)
交通部重点科技项目(2003319H01010)
广东省交通科技项目(200701)
关键词
拉索减振
黏性剪切阻尼器
对数衰减率
斜拉桥
Vibration reduction of stayed-cable
Viscous shearing damper
Logarithmic decrement ratio
Cable-stayed bridge
