基于弹性索和摩擦摆支座的纵飘桥梁振动控制研究

发布时间：2019-03-01 19:37

【摘要】：近年来,随着中国社会经济的高速发展,作为交通枢纽的大跨度桥梁迅速被修建。纵飘桥梁是大跨度桥梁设计中一种比较常见的结构形式,该桥型的特点是纵向无约束,允许主梁纵向摆动,具有良好的耗能减振效果,但在地震荷载和车辆制动力作用下会产生较大的梁端纵向位移,影响桥梁的正常使用,甚至导致落梁,因此有必要采取相应的措施进行控制。本文以佛山平胜大桥为工程背景,分别进行了车辆制动力和地震荷载作用下基于弹性索和摩擦摆支座的减振(震)控制研究。主要研究内容如下： (1)应用有限元软件MIDAS,建立了佛山平胜大桥的空间有限元模型。动力特性分析结果表明：纵飘桥梁结构体系的固有频率为0.0643Hz,纵向刚度小；弹性索和摩擦摆支座能够有效的提高桥梁的纵向刚度。 (2)基于MIDAS模型,利用时程分析法,进行了车辆制动力作用下的减振控制研究。结果表明：在车辆制动力作用下,弹性索对于主梁纵向位移的控制作用相当显著；同时对温度和主跨满布两种正常运营状态具有较好的适应性。 (3)采用正交试验法对摩擦摆支座的参数进行比选,并对参数优选后的摩擦摆支座进行了减震控制研究。结果表明,摩擦摆支座具有较好的减震控制效果,在平胜桥实桥波、El-Centro波、Taft波作用下,主梁梁端位移分别减小了26.75%、19.27%、36.46%。 (4)运用ANSYS开展了基于弹性索和摩擦摆支座的减震控制研究,结果表明：在地震荷载作用下对于主梁纵向位移的控制作用主要来自摩擦摆支座,为减小车辆制动力作用下主梁纵向位移而设置的弹性索在地震荷载作用下预期被拉断。
[Abstract]:In recent years, with the rapid development of social economy in China, the long-span bridge, as a transportation hub, has been built rapidly. Longitudinal floating bridge is a common structural form in the design of long-span bridge, which is characterized by longitudinal unconstrained, allowing the main beam to swing longitudinally, and has good energy dissipation effect. However, under the action of earthquake load and vehicle braking force, large longitudinal displacement of beam end will be produced, which will affect the normal use of bridge and even lead to beam falling, so it is necessary to take corresponding measures to control it. In this paper, based on the engineering background of Pingsheng Bridge in Foshan, the vibration reduction (earthquake) control based on elastic cable and friction pendulum bearing under vehicle braking force and earthquake load is studied respectively. The main contents are as follows: (1) the spatial finite element model of Foshan Pingsheng Bridge is established by using finite element software MIDAS,. The results of dynamic analysis show that the natural frequency of the longitudinal floating bridge system is 0.0643Hz, the longitudinal stiffness is small, and the elastic cable and friction pendulum support can effectively improve the longitudinal stiffness of the bridge. (2) based on MIDAS model and time-history analysis, the vibration control of vehicle under braking force is studied. The results show that the control effect of elastic cable on longitudinal displacement of main beam is quite remarkable under the action of vehicle braking force, and the elastic cable has good adaptability to two normal operating conditions: temperature and main span full distribution. (3) the parameters of the friction pendulum bearing are selected by orthogonal test method, and the damping control of the friction pendulum bearing after the optimization of the parameters is studied. The results show that the friction pendulum bearing has better seismic control effect. Under the action of the real bridge wave, El-Centro wave and Taft wave of Pingsheng Bridge, the displacement of the main beam end decreases by 26.75%, 19.27% and 36.46%, respectively. (4) the research of damping control based on elastic cable and friction pendulum bearing is carried out by using ANSYS. The results show that the control effect of longitudinal displacement of main beam under earthquake load mainly comes from friction pendulum support. The elastic cable set up to reduce the longitudinal displacement of the main beam under the action of vehicle braking force is expected to be broken under the action of earthquake load.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.3

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