【作者】 赵津扬；

【导师】 张琪昌；

【作者基本信息】 天津大学 ， 工程力学， 2008， 硕士

【摘要】 由于大跨度斜拉桥拉索频率低、阻尼小等特点,因此容易诱发各种风致振动,斜拉桥拉索的风雨激振现象便是其中的一种。风雨激振现象是在风和雨的共同作用下,斜拉桥拉索发生的一种具有很大破坏性的激烈的大幅振动。由于发生频繁且危害性大,风雨激振已成为目前世界桥梁抗风研究的难点和热点之一。而风雨激振发生的机理比较复杂,是一种复杂的流固耦合问题,所以它的理论研究进展比较缓慢。索结构的风雨振研究涉及到流体力学、非线性动力学以及结构力学等多门学科领域,它作为一类特殊的连续体,存在明显的几何非线性等特点。在风雨载荷作用下,由于水线位置的变化导致的索结构气动弹性更加复杂,使得其动力学行为的研究比一般的动力学研究更难,这也是索结构风雨激振的理论研究进展比较缓慢的主要原因之一。本文尝试利用力学分析从流体和固体两个方面对风雨激振的参数机理和气动减振措施进行研究,实现的内容包括:(1)利用FLUENT软件分析了斜拉桥拉索在不同情况下的流场情况并计算其升阻力系数。(2)建立了斜拉桥拉索抛物线形状的三维连续体有限元模型,并利用ANSYS对其进行有限元了静力分析和模态分析。考虑到风雨激振影响参数较多,利用FLUENT得到的系数计算其气动力,实现初步的流固耦合,逐步对其每个影响因素进行细化分析并得到相关的变化规律,与实验结果基本相符。(3)根据风雨激振分析理论,介绍常用的控制与减振措施,利用ANSYS进行数值模拟试验,对阻尼器减振、气动减振和辅助索减振等方法进行动力特性分析,与前面的分析进行对比,探讨各种减振措施合理性,并得到了可行性结论。更多还原

【Abstract】 Cables in large-span cable-stayed bridge due to low frequency, small damping, easily evoked various wind-induced vibration, the rain-wind induced vibration phenomenon of cables in cable-stayed bridge is one of them. Rain-wind induced vibration induced by the wind and rain in the common role, is very destructive fierce substantial vibration. As rain-wind induced vibration happens frequently and harmfully, it has become one of the world difficult and hot research spots, and that the rain-wind induced vibration mechanism is quite complex, is one kind of intricate FSI problem, so the excitation has relatively slow progress in theoretical research.Cable structure of rain-wind induced vibration involves fluid dynamics, structural mechanics and nonlinear dynamics, and other subject areas. As a special kind of continuum, there is an obvious characteristic of the non-linear geometry . In the wind and rain load, as water line leading to changes in location of the cable structure, more complex and dynamic behavior makes its research more complicated than the general study of the dynamics, this is the main reason why wind-rain induced vibration research progresse quite slow. The research work considered the fluid and solid aspects, parameters of the rain-wind induced vibration and damping mechanism measures are studied by using mechanics analysis software in this article:(1) The research work used FLUENT in rain-wind induced vibration under different circumstances to analyse the liquid field and to calculate its lift and drag coefficient.(2) The paper founded a cable of 3-D continuous parabolic shape finite element model in cable-stayed bridge and used it to make static analysis and mode analysis in ANSYS. It was considered the impact of the rain-wind induced parameters more exciting, used FLUENT to calculate its aerodynamics. The paper initially realized the solid-fluid interaction, gradually researched each of its influencing factors by detailed analysis, and we get the results which match with the experimental data.(3) According to the rain-wind induced excitation analysis theory, the paper introduced common kinds of control and the damping measures, analyzed several kinds of numerical simulation experiment by using ANSYS, such as the attenuator absorbing vibration, air operated damping and the auxiliary rope damping method and so on, carried on the contrast with the front result, discussed each shock absorption measure rationality, and obtained the feasible conclusions.更多还原