刘家峡桁架梁悬索桥的颤抖振时域分析

以刘家峡大桥为工程背景,建立了钢桁架梁悬索桥的有限元模型,采用改进谐波合成法模拟了脉动风荷载,结合大跨桥梁颤抖振分析的基本理论,计算了对应于桥梁各节点的静风力、抖振力和自激力.在此基础上,利用ANSYS参数化设计语言（APDL）编制了相应的计算程序,将计算所得的各类风荷载施加在全桥有限元模型的节点上,对刘家峡桁架梁悬索桥进行了颤抖振时域分析,以精确求解不同桥面基准风速下,桥梁各关键部位的抖振扭转角、抖振侧向位移、抖振竖向位移,进而研究了风速变化对悬索桥最大颤抖振响应的影响.与全桥模型风洞试验的对比结果表明：对大跨桥的颤抖振分析方法是合理可行的,可为同类大跨桥梁风致振动的研究提供科学的依据和参考.

Trembling vibration of Liujiaxia steel truss suspension bridge based on time domain analysis

Based on Liu-jia-xia Bridge,a FEA model of steel truss suspension bridge is established.Meanwhile,perfect stochastic fluctuating wind field processes are generated by using improved WAWS method.Combined with the basic theory for tremble vibration analysis of large span bridge,static wind force,buffeting force and self-excited force are computed according to the nodes of bridge.By using ANSYS parametric design language,one calculation program is prepared to apply the calculated wind loads on the nodes of FEA model.Based on time domain analysis,the trembling vibration of Liu-jia-xia steel truss suspension bridge is carried on to compute buffeting torsion angle,chattering lateral displacement and vertical displacement chattering of some principle parts of bridge.The effects of wind speed on max trembling vibration of truss suspension bridge are studied.Compared with the result of wind tunnel test of whole bridge,it can be known that the tremble vibration analysis method suggested in this paper is reasonable and feasible.So,some meaningful references are provided for the further research on wind-induced vibration for long-span bridges.