流线闭口箱梁断面涡振过程分布气动力演变特性

发布时间：2018-07-09 15:28

本文选题：流线型闭口箱梁 + 涡振过程　；参考：《哈尔滨工业大学学报》2017年12期

【摘要】：涡激振动是大跨度桥梁在低风速下较常见的风致振动现象,探究涡振机理是桥梁涡激振动效应评价与控制的重要前提.为深入研究涡振机理,立足于涡振发展的完整过程分布气动力与结构行为同步演变特性分析,深入揭示了分布气动力及其结构行为作用机制.以典型大跨度桥梁闭口流线型箱梁断面为对象,实现了弹性悬挂节段模型同步测力、测振和测压风洞试验.针对典型涡振过程风速关键结点,对比研究了涡振发生前、锁定区上升区、振幅极值点、下降区以及涡振后等不同时期箱梁表面分布气动力演变特性.研究表明,涡振过程箱梁分布气动力特性具有明显的变迁历程,集中体现在涡振锁定区内外表面气动力特性具有显著差异,压力系数根方差、振动卓越频率处压力系数等统计参数与涡振振幅高度相关,气动力与涡振振幅具有明显同步演化关系,尤其是上表面下游、下表面与下游风嘴转角附近区域气动力演变特性显著,是引起涡振的主要原因.该研究为涡振机理研究提供了一种新的思路和方法,未来可应用于其他类型主梁断面.
[Abstract]:Vortex induced vibration is a common phenomenon of wind induced vibration of long-span bridges under low wind speed. To explore the mechanism of vortex vibration is an important prerequisite for the evaluation and control of bridge vortex induced vibration effect. A typical large span bridge closed streamlined box girder section is used to realize the synchronous force measurement, vibration measurement and pressure testing in a typical large span bridge. According to the key nodes of the typical vortex vibration process, the rise area of the locking region, the amplitude extreme point, the descending area and the vortex vibration before the vortex vibration are compared and studied. It is shown that the aerodynamic characteristics of the box girder in the vortex vibration process have a distinct evolution process, and the aerodynamic characteristics of the inner and outer surfaces of the vortex vibration lock-in area have significant difference, the pressure coefficient root variance, the pressure coefficient and the vibration amplitude, and the vortex vibration amplitude. The relationship between the aerodynamic force and the amplitude of the vortex vibration is obviously synchronized, especially the downstream of the upper surface, and the aerodynamic evolution characteristics of the lower surface and the downstream corner of the nozzle are significant, which is the main cause of the vortex vibration. This study provides a new way of thinking and method for the study of the mechanism of vortex vibration. The future can be applied to other types of main beams. Section.
【作者单位】：土木工程防灾国家重点实验室(同济大学);浙江省交通规划设计研究院;
【基金】：国家自然科学基金(51323013,51678451) 新世纪优秀人才支持计划(NCET-13-0429)
【分类号】：U441.3

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