摘要
将水平抗风索对钢拱桥H型刚性吊杆的约束作用简化为水平弹簧的弹性支承作用,推导了一对水平抗风索的等效扭转弹簧弹性支承刚度计算公式,基于建立的H型吊杆-水平抗风索耦合系统扭转振动理论模型,相应提出了耦合系统扭转自振特性求解理论方法,并通过有限元法验证了该方法的准确性;分析了抗风索位置、刚度参数对H型吊杆扭转自振特性的影响规律,据此提出了水平抗风索对H型吊杆第1阶扭转模态振动控制的参数设计方法。研究表明:抗风索安装位置不同,其等效扭转刚度对耦合系统扭转自振特性的影响程度也不同,且抗风索位置决定了耦合系统扭转自振频率增长极限值;抗风索等效扭转刚度决定了吊杆扭转振型结点个数;当仅考虑H型吊杆第1阶扭转振动模态控制时,宜将抗风索设置在吊杆中心位置处,此时随着抗风索等效扭转刚度的逐渐增大,吊杆第1阶扭转自振频率将超越第2阶,相应扭转振型在抗风索位置处的振型节点坐标逐渐趋于0,即吊杆变为几乎完全独立的两段。该文研究成果可为H型吊杆的水平抗风索减振优化设计提供重要依据。
The restriction effect of horizontal wind-resistant cables on rigid H-Section hangers in steel arch bridges was simplified to be the support of horizontal springs.On this basis,equivalent torsional stiffness of a pair of horizontal wind-resistant cables was derived,and a theoretical model of the coupled system with hangers and wind-resistant cables was established for Hsection hangers.A theoretical method for coupled system with H-section hangers and wind-resistant cables was proposed to solve torsional free vibration characteristics,whose accuracy was verified through the finite element method.The effects of locations and stiffness of wind-resistant cables on free torsional vibration characteristics of H-section hangers were analyzed.Finally,parameter design method of wind-resistant cables for torsional vibration control of H-section hangers was developed.The results show that the incidence effect of equivalent torsional stiffness on free torsional vibration characteristics of coupled system is not the same with different locations of wind-resistant cables,and the ultimate natural frequencies of coupled system are controlled by the wind-resistant cables location.The numbers of torsional mode shape nodes for H-section hanger are determined by the wind-resistant cables stiffness.Considering the first-order torsional vibration control,the wind-resistant cables should better be installed at the mid-point of a hanger.The second-order torsional natural frequencies are exceeded by the firstorder torsional natural frequencies,and the first-order torsional modal coordinate at the cables gradually tend to zero with the increasing equivalent torsional stiffness of the wind-resistant cables,which indicates that one hanger has been divided into almost two independent segments by the wind-resistant cables.The main founding of this paper can provide optimal design basis for vibration control of H-section hangers with horizontal wind-resistant cables.
出处
《振动工程学报》
EI
CSCD
北大核心
2017年第4期620-629,共10页
Journal of Vibration Engineering
基金
国家自然科学基金资助项目(51308214)
国家重点基础研究973计划项目(2015CB057702)
河南省高等学校青年骨干教师资助计划(2015GGJS-104)
河南省教育厅科学技术研究重点项目(13A560711)
河南省高校科技创新团队支持计划(15IRTSTHN028)
关键词
水平抗风索
钢拱桥
H型吊杆
等效扭转刚度
扭转自振特性
horizontal wind-resistant cable
steel arch bridge
H-section hanger
equivalent torsional stiffness
torsional dy- namic characteristic
作者简介
汪志昊（1980-），男，博士，副教授。电话：（0371）65790237；E-mail：wangzhiha0916@126．com
