气动措施抑制钝体箱梁竖向涡振的风洞试验研究

发布时间：2018-03-08 15:50

本文选题：斜拉桥　切入点：箱形梁　出处：《桥梁建设》2014年01期 　论文类型：期刊论文

【摘要】：为研究钝体箱梁发生竖向涡振的内在特性及气动措施抑振的规律,采用风洞试验同步测量箱梁模型的振动位移和表面压力。基于模型各测点的压力时程,综合对比分析压力系数均值与均方差值、局部气动力对总体气动力的相关性与贡献程度。结果显示:钝体箱梁断面发生竖向涡振的根本原因是上游分离的气流使得中、下游脉动压力显著增大,中、下游升力对总体升力具有良好的相关性,且对涡激振动贡献最大;封闭栏杆方式可以抑制钝体箱梁断面的竖向涡振;栏杆阻风率变化会同时改变钝体箱梁上、下表面的压力脉动分布强度,但只能改变其上表面的压力系数均值;气动措施抑振的机理是其削弱了箱梁中、下游的脉动压力强度,破坏了局部升力对总体升力的相关性。
[Abstract]:In order to study the inherent characteristics of vertical vortex vibration of blunt body box girder and the law of vibration suppression by pneumatic measures, the vibration displacement and surface pressure of box girder model are measured synchronously by wind tunnel test. Based on the pressure time history of each measuring point of the model, the vibration displacement and surface pressure of the box girder model are measured simultaneously by wind tunnel test. The correlation and contribution of local aerodynamic forces to the total aerodynamic force are compared and analyzed comprehensively. The results show that the fundamental cause of vertical vortex vibration in the section of blunt body box girder is caused by the separation of upstream airflow. The downstream pulsating pressure increases significantly, and the downstream lift has a good correlation to the overall lift, and the contribution to the vortex-induced vibration is the greatest, and the closed railing can restrain the vertical vortex vibration of the obtuse box girder section. The variation of balustrade wind resistance rate will change the distribution intensity of pressure pulsation on the upper and lower surface of the box girder, but can only change the mean value of the pressure coefficient on the upper surface of the box girder, and the mechanism of the aerodynamic measures is that it weakens the pulsating pressure intensity in the middle and lower reaches of the box girder. The correlation between the local lift and the total lift is destroyed.
【作者单位】：长安大学公路学院;长安大学风洞试验室;华北水利水电大学土木与交通学院;
【分类号】：U448.213;U446.1

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