摘要
π型主梁断面涡激共振是影响其在大跨度桥梁中广泛使用的重要因素之一。以某大跨度超高三塔斜拉桥为工程背景,采用节段模型测试了施工状态主梁涡振性能,试验发现在设计风速范围内主梁存在明显的竖向涡激共振现象,且在规范规定的阻尼比范围内涡振振幅均大于规范限值;为抑制主梁涡振,设计了隔流板和下稳定板等气动减振措施。结果表明:一定宽度的隔流板虽然能降低主梁涡激共振振幅,但其减振效果有限;两道一定长度的下稳定板能较好的抑制主梁涡激共振,且满足颤振稳定性要求;最后,结合数值模拟的方法对涡振发生及减振机理进行了初步探讨。
πtype cross-section of main beam vortex-induced vibration(VIV)is one of important factors influencing its wide-spread usage in long-span bridges.Taking a super high cable-stayed bridge with three towers as a certain engineering background,its VIV performances in a construction state were investigated with a sectional model in wind tunnel.Test results showed that the bridge suffers remarkable VIV within the designed wind velocity range;within the specified range of damping ratio in the code,amplitudes of the bridge’s VIV are larger than the specified value in the code;in order to suppress VIV of the main beam,flow-isolating plates and lower stabilizers are designed as aerodynamic vibration-reduction measures;the vibration-mitigation effect of flow-isolating plates seems to be limited,however,lower stabilizers have a better VIV-suppressing effect,they also satisfy the requirements of flutter stability.Finally,the mechanism for VIV-generating and suppressing was preliminarily discussed with CFD numerical simulation method.
作者
李欢
何旭辉
王汉封
刘梦婷
彭思
LI Huan;HE Xuhui;WANG Hanfeng;LIU Mengting;PENG Si(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Lab for High Speed Railway Manufacture Technology,Central South University,Changsha 410075,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2018年第7期62-68,共7页
Journal of Vibration and Shock
基金
国家自然基金资助项目(51508580
51508574)
中南大学"创新驱动计划"项目(2015CX006)
关键词
π型断面
涡激共振
减振措施
风洞试验
计算流体动力学
π-section
vortex-induced vibration(VIV)
vibration-reduction measures
wind tunnel test
compotational fluid dynamics(CFD)
