MR阻尼器半主动控制对拉索减振效果的仿真分析  

SIMULATION ANALYSIS FOR VIBRATION MITIGATION OF STAY-CABLE BY MR DAMPERS UNDER SEMI-ACTIVE CONTROL STRATEGY

作　　者：邬喆华[1] 楼文娟[2] 陈勇[2] 朱瑶宏[3] 唐锦春[2] 

机构地区：[1]同济大学土木工程学院 [2]浙江大学土木工程系,浙江杭州310027 [3]杭州湾大桥工程指挥部,浙江宁波315327

出　　处：《工程力学》2007年第10期11-18,24,共9页Engineering Mechanics

基　　金：中国博士后科学基金资助项目(2005037512);宁波博士基金项目(2005A610028)

摘　　要：为控制斜拉索的大幅振动,在Hamilton原理基础上应用Galerkin法建立了斜拉索动力计算模型。采用基于位移和速度方向的半主动控制算法,对某大桥330m长斜拉索和MR阻尼器组成的系统进行了动力分析,以全索全时段振动响应的均方根作为振动控制效果的评价指标。磁流变阻尼器力学关系选用Spencer现象模型。比较了MR阻尼器半主动控制与被动控制对斜拉索前三阶的减振效果,对MR阻尼器耗能机理和半主动控制算法的实用性进行了探讨。同时考察了系统的共振峰频率漂移及滞回曲线形状,提出了理想的粘性可变阻尼器模型。分析表明:基于位移和速度方向半主动控制的算法简单、易于操作、安全可靠且对长索多阶振动模态亦能取得较好的减振效果,优于被动控制。MR阻尼器的制振效果主要来自耗能,调频作用较小。Long-span cables are susceptible to vibration with large amplitude under wind/rain loadings or support excitations. To overcome these problems, a theoretic model based on the Hamilton principle for the cable-damper system is formulated by accounting for the cable inclination and sag effect. The discrete Magneto-Rheological （MR） dampers are installed on the 330m-long cable in a stay-cable bridge. The dynamic response performances of a cable with MR dampers are explored by using Spencer photometric model. Based on the direction of both displacement and velocity, the semi-active control strategy of cable vibration is proposed. The primary measure of damper performance is the Root Mean Square （RMS） considered cable deflection integrated along the length of the cable and the whole time period. The comparison study among the semi-active under the strategy and the optimal passive MR damper has shown the advantages of semi-active dynamic adjust control when MR dampers marker is within the effective region. The strategy is robust and quite easy to be applied for fewer necessary sensors. The dynamic range of MR dampers is sufficiently wide. The resonant frequencies of the cable installed MR dampers have a little change. It implies that MR dampers under semi-active control strategy can significantly reduce long cable vibration.

关 键 词：桥梁工程 斜拉索 数值仿真 磁流变阻尼器 振动控制 

分 类 号：TU311.3[建筑科学—结构工程] U448.27[建筑科学—桥梁与隧道工程]