钢桁梁箱形下弦杆受压承载试验及模拟修正研究  

Study on Load-bearing Test and Model Updating of Box Lower Chord of Steel Trussed Girder

作　　者：夏智 XIA Zhi(Transportation and Logistics Engineering,Wuhan University of Technology,Wuhan 430063,China)

机构地区：[1]中铁大桥局集团第六工程有限公司,武汉430100

出　　处：《交通科技》2023年第2期67-72,共6页Transportation Science & Technology

基　　金：国家自然科学基金项目(51178361);湖北省交通运输厅科技项目(2022-11-2-8)资助。

摘　　要：以某长江公路大桥钢桁梁最不利节段处的箱形下弦杆为研究对象,通过畸变缩尺模型的轴压承载能力实验和非线性屈曲模型,研究下弦杆的破坏形态与力学特性,为验证设计年限内桥梁杆件的稳定性和受力特性提供数据支撑。实验和模拟结果表明:在轴向压力作用下,杆件在1/2截面附近发生局部屈曲,从而导致整体的屈曲破坏,但实验的极限承载荷载与欧拉临界公式计算结果存在较大误差;通过分析认为误差是由边界条件引起的,在对模型边界条件进行调整后,模拟结果更加符合实验结果,说明边界条件是引起实验和理论极限承载荷载误差的因素之一。Taking the box-shaped lower chord rod at the most unfavorable section of the steel truss of a Yangtze River Highway Bridge as the research object,the failure form and mechanical characteristics of the lower chord rod are studied through the axial pressure bearing capacity experiment and nonlinear buckling model of the distortion scale model,which provides data support for verifying the stability and force characteristics of the bridge members during the design period.The experimental and simulation results show that under the action of axial pressure,local buckling occurs near the 1/2 height section of the member,resulting in the overall buckling failure.However,there is a large error between the experimental ultimate load and the calculation result of Euler critical formula.Through the analysis,it is considered that the error may be caused by the boundary conditions.After adjusting the boundary conditions of the model,the simulation results are more in line with the experimental results,which shows that the boundary conditions are one of the factors causing the error in the experimental and theoretical ultimate bearing load.

关 键 词：钢桁梁 非线性屈曲 弧长法 压杆稳定 

分 类 号：U441[建筑科学—桥梁与隧道工程]