摘要
以某大跨度窄桥面钢桁架悬索桥为工程背景,运用大型通用有限元软件ANSYS14.5建立动力有限元模型,采用谐波合成法模拟脉动风场,基于大跨度桥梁抖振时域分析基本理论,计算了对应于桥梁主梁各节点的静风力、抖振力和自激力,据此运用APDL语言编制抖振时域计算程序;将计算出的风荷载施加到全桥有限元模型节点上,对大跨度窄桥面钢桁架悬索桥进行抖振时域分析,探讨了气动导纳函数和自激力对桥梁抖振响应的影响。计算结果表明:在桥梁基准风速条件下,主梁1/4跨点和跨中点竖向和横向抖振位移值相近,跨中处扭转角大于两边跨处;考虑气动导纳函数后,桥梁抖振位移明显减小,而考虑气动自激力后,桥梁抖振位移则增大,气动导纳函数和自激力对桥梁抖振响应有较大影响。
A dynamic finite element model of a long-span narrow deck steel truss suspension bridge was established by using ANSYS14.5.Harmonic synthesis method was used to simulate the fluctuating wind field.The static wind load,buffeting load and self-excited load were calculated based on the basic theory of long-span bridge buffeting analysis in time domain.The buffeting time domain analysis program was worked out by using APDL language.The calculated wind load was added to the finite element model nodes for buffeting time domain analysis.The effects of aerodynamic admittance function and self-excited load on bridge buffeting response were discussed.The results show that the vertical and horizontal buffeting displacements at mid-span are close to those at quarter-span,but the torsion angles at mid-span are greater than those at quarter-span under the condition of bridge base wind speed.The aerodynamic admittance function obviously decreases the bridge＇s buffering displacements,but the displacements will increase if self-excited force is considered.Thus,aerodynamic admittance function and self-excited force have a great influence on buffeting response of the bridge.
出处
《铁道建筑》
北大核心
2016年第11期10-14,共5页
Railway Engineering
基金
国家自然科学基金(51408557)
中国博士后科学基金(2013M541995)
关键词
大跨度悬索桥
窄桥面
钢桁架梁
抖振
时域分析
Long-span suspension bridge
Narrow deck
Steel truss
Buffeting
Time domain analysis
