稳定板高度对桥面输送机边主梁斜拉桥涡振性能的影响机理  

Influence mechanism of stabilizer height on vortex induced vibration performance of side girder cable stayed bridge with deck conveyor

作　　者：李春光 毛禹 颜虎斌 韩艳 周旭辉 LI Chun-guang;MAO Yu;YAN Hu-bin;HAN Yan;ZHOU Xu-hui(School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,Hunan,China)

机构地区：[1]长沙理工大学土木工程学院,湖南长沙410114

出　　处：《长安大学学报（自然科学版）》2022年第2期56-67,共12页Journal of Chang’an University(Natural Science Edition)

基　　金：国家自然科学基金项目(51978087,51822803);湖南省自然科学基金项目(2020JJ14607)。

摘　　要：为研究不同高度梁底中央稳定板对桥面安装输送机的边主梁桥涡振性能的影响,通过节段模型风洞测振、测压试验获取主梁在下中央稳定板作用下的涡振性能和压力时程数据,并综合对比分析了主梁在3种不同高度稳定板作用下的脉动压力系数均值、均方差、功率谱、局部与总体气动力的相关性。结果表明:稳定板对边主梁断面气动稳定性的提高具有良好的效果,高度1 m和1.5 m下中央稳定板对主梁涡振响应的作用基本一致,使峰值响应约降低了25%,而伸出梁底0.5 m(即高度2 m下中央稳定板)能完全抑制主梁涡振响应。竖弯涡激共振发生的主要原因是上表面前部分离与再附区域强烈的压力脉动,下表面前部气动力与总体气动力的强相关性以及后部具有明显相关性的强烈压力脉动;增设高度1 m和1.5 m下中央稳定板对表面流场分布影响较小,但上表面和下表面大部分区域的压力脉动随稳定板高度的增加逐渐降低,主梁涡振响应被削弱;下表面稳定板后部区域相关性降低,同时其脉动压力增强,从而造成主梁在2种高度稳定板作用下涡振响应一致;增设高度2 m下中央稳定板,稳定板后部部分测点的涡脱频率仍集中在模型的竖弯频率,但能量较低,上下表面与总体气动力的相关性不同程度破坏,压力脉动大幅削弱,涡激共振得到完全抑制。In order to study the influence of the central stabilizer plate at the bottom of the beam on the vortex induce vibration performance of the side main beam bridge with conveyor installed on the bridge deck,the vibration performance and pressure time history data of the side main beam under the action of the lower central stabilizer plate were obtained,through the wind tunnel vibration measurement and pressure test of the section model.Then the mean value,mean square deviation,power spectrum and the correlation between local and overall aerodynamic forces of the fluctuating pressure coefficient of the main beam under the action of three kinds of stable plates with different heights were comprehensively compared and analyzed.The results show that the stabilizing plate has a good effect on improving the aerodynamic stability of the side main beam section.The effect of the central stabilizer plate on the vibration response of the girder is basically the same when the height is 1 m and 1.5 m,which reduces the peak response by about 25%,while the central stabilizer plate can completely suppress the vibration response of the girder,when it extends out of the bottom of the girder by 0.5 m(the lower central stabilizer plate is 2 m high).The analysis of pressure measurement data reveals that the main causes of vortex induced vibration are the strong pressure pulsation in the separation and reattachment area at the front of the upper surface,the strong correlation between the front aerodynamic force and the overall aerodynamic force at the lower surface,and the strong pressure pulsation with obvious correlation at the rear.The effect of adding lower central stabilizer of 1 and 1.5 m has little influence on the surface flow field distribution,but the pressure fluctuation of most areas of the upper and lower surfaces gradually decreases with the increase of the height of the stabilizer,and the vibration response of the main girder is weakened.The correlation of the rear area of the stabilizer plate on the lower surface decreas

关 键 词：桥梁工程 涡振 风洞试验 下中央稳定板 制振机理 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]