Tacoma大桥风振致毁事故机理分析与模拟-《中国安全生产科学技术》

文章信息/Info

Title:: Mechanism analysis and simulation of tacoma narrow bridge accident caused by wind vibration breaking

Author(s):: ZHAO Qing-xian; GE Xiu-kun; SHAO Hui; School of Environment and Safety Engineering,Changzhou University,Changzhou 213164,China

Keywords:: tacoma narrow bridge; symmetry breaking; simulation; pressure low area; wind vibration

摘要:: 以Tacoma大桥风振致毁事故为例,从流体力学的角度系统分析了气流绕过桥体时流场对称性的破缺及其诱发桥梁振动的机理;并通过建立数值计算模型,采用Fluent软件对其进行了仿真计算。结果显示:当风速超过1m/s时,桥面上下侧压力对称性开始破缺,低压区从桥面的正下方(或正上方)逐渐向右移动,跨过右边墙后消失,同时在相反的一侧逐步形成低压区,然后又向右移动并逐渐消失,如此周期交替变化,并且在不同的风速条件下,交替变化的频率不同,其值随着风速的增加而逐步增大,但增长速率却随着风速的增加逐渐减小。

Abstract:: Taking Tacoma Narrow Bridge accident caused by wind vibration for an example,flow symmetry breaking by the flow around the bridge and mechanism of the bridge vibration were analyzed in view of hydrodynamics.Numerical models were set up and Fluent software was used to finish simulation calculation.The results showed that lateral pressure symmetry in the upper and lower bridge deck began to break with wind velocity > 1m/s.The Pressure low area moved to the right from the underside(or top)of the bridge deck and disappeared when striding the right of the wall.At the same time the pressure low area was gradually formed at the opposite,then moved to the right,disappeared and changed alternately and periodically.And the alternate frequency was different on the different wind speed conditions.The frequency value increased as wind speed increased.But the increasing rate decreased as wind speed increased.