双开槽箱梁主梁气动力负斜率效应及其三维静风屈曲后承载行为  

NEGATIVE AERODYNAMIC SLOPE EFFECT OF DOUBLE SLOTTED BOX GIRDER AND BEARING BEHAVIOR OF THREE DIMENSIONAL STATIC WIND AFTER BUCKLING

作　　者：罗松 崔巍[1,2] 赵林 葛耀君[1,2] LUO Song;CUI Wei;ZHAO Lin;GE Yao-jun(State Key Lab of'Disaster Reduction in Civil Engineering,Tongi University,Shanghai 200092,China;Key Laboratory of'Transport Industry of Wind Resistant Technology for Bridge Structures,Tongi University,Shanghai 200092,China;School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092 [2]同济大学桥梁结构抗风技术交通运输行业重点实验室,上海200092 [3]重庆交通大学土木工程学院,重庆400074

出　　处：《工程力学》2025年第3期56-67,共12页Engineering Mechanics

基　　金：青年科学基金项目(5200081408)。

摘　　要：基于双开槽主梁断面,通过改变断面的气动外形,让断面具有静风屈曲后继续承载能力,并分析断面三分力系数与静风屈曲后变形的关系以及静风屈曲失稳的机理。主要研究目标是,通过改变断面的开槽宽度和斜腹板角度等气动外形参数,基于CFD数值模拟并利用风洞试验验证的方法计算断面的三分力系数,选出具有负斜率趋势的桥梁主梁断面;在综合考虑构几何非线性和静风荷载非线性的基础上,采用弧长法迭代计算,计算结构主梁静风失稳后完整过程的位移响应。研究结果表明:开槽宽度和斜腹板角度都可使CL和CM曲线斜率变负,一起改变这两个参数时负斜率效果更明显;初始攻角会影响最终失稳风速和结构是否存在屈曲后;三分力系数曲线斜率变负,降低了静风荷载随变形的增加速率,使桥梁静风屈曲后具有继续承载能力,这使桥梁抵抗静风荷载有了“韧性”,提高了安全储备。Based on the double-slotted shape,the aerodynamic shape of the bridge section is optimized to enable the long-span bridge to have the continuous bearing capacity after aerostatic buckling,and analyzed are the relationship between the aerodynamic force coefficients and the deformation after aerostatic buckling.The main research objective is to select the shape of bridge main girder section with negative slope tendency by changing the aerodynamic shape parameters such as the width of the slot and the angle of the inclined web,based on CFD numerical simulation and using the method of wind tunnel test to calculate the three-component coefficient of the cross section.Considering both nonlinearity of structure geometry and aerodynamic force,the arc length method is used to calculate the displacement of the main girder after the aerostatic instability.The results show that:the slotting width and oblique web angle can make the slope of CL and CM curves negative,and the negative slope effect is more obvious when the two parameters are changed together.The initial angle of attack will affect the final wind speed of instability and whether the structure has post-buckling.The slope of the three-directional force coefficient curve becomes negative reduces the increasing rate of static wind load with deformation,which can make the bridge has continued bearing capacity after static wind buckling.This increase the bridge resilience against static wind load and,improves the wind safety reserve.

关 键 词：CFD数值模拟 三分力系数负斜率 弧长法 静风屈曲失稳 抗灾韧性 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]