超高钢管支架风致动力响应分析与数值模拟

Analysis and numerical simulation of wind-induced dynamic response of ultra-high steel pipe supports

以重遵扩容项目工程为依托,采用流体力学软件ANSYS Fluent虚拟风洞,计算出超高钢管支架周围流场特性和三分力系数;基于谐波合成法采用Kaimal沿高度变化的风速谱,使用MATLAB对高桥上任意点进行横向脉动风速的模拟,将脉动风荷载施加到Midas Civil建立的超高钢管支架动力学模型,以研究脉动风对超高钢管支架的风致振动响应.研究结果表明:其升力系数、升力矩系数和阻力系数分别为0、-100和400,流场性质也与理论相符合.对超高钢管支架的模态分析结果显示,贝雷梁比较容易发生扭转振动,无边界约束的钢管柱易发生横桥向的简谐振动,在搭设支架和混凝土浇筑的施工过程中要注意其质量,做到实时监控,以免发生破坏而造成较大的事故.通过计算超高钢管支架的动力响应得到支架的最大位移为0.4286 m,最大加速度为2.3149 m/s^(2).结果表明此超高钢管支架的动力响应产生的支架水平位移过大,应加强支架的稳定及限制其水平位移.

Relying on the actual engineering of the capacity expansion project,using the fluid mechanics software ANSYS Fluent virtual wind tunnel,the flow field characteristics and the three-component force coefficient around the ultra-high steel pipe support are calculated;based on the harmonic synthesis method,the wind speed spectrum of the Kaimal along the height is used,Use MATLAB to simulate the lateral fluctuating wind speed at any point on the high bridge,and apply the fluctuating wind load to the dynamic model of the ultra-high steel pipe support established by Midas Civil to study the wind-induced vibration response of the ultra-high steel pipe support by the pulsating wind.The research results show that the lift coefficient,lift moment coefficient and drag coefficient are 0,-100 and 400respectively,and the properties of the flow field are also consistent with the theory.The modal analysis results of the ultra-high steel tube support show that the Bailey beam is more prone to torsional vibration,and the steel tube column without boundary constraints is prone to simple harmonic vibration in the transverse direction.Pay attention to this during the construction process of erecting the support and concrete pouring.The quality should be monitored in real time to avoid major accidents caused by damage.By calculating the dynamic response of the ultra-high steel pipe support,the maximum displacement of the support is 0.4286 m,and the maximum acceleration is 2.3149 m/s^(2).The results show that the horizontal displacement of the support caused by the dynamic response of this ultra-high steel pipe support is too large,and the stability of the support should be strengthened and its horizontal displacement should be limited.