车道荷载作用下箱梁应力放大系数的解析法研究  

Analytical Study on Stress Amplification Factor ofBox Girders Subjected to Lane Load

作　　者：陈玮珂 张元海[1] CHEN Weike;ZHANG Yuanhai(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070

出　　处：《兰州交通大学学报》2024年第2期1-6,共6页Journal of Lanzhou Jiaotong University

基　　金：国家自然科学基金(52368020,51968040)。

摘　　要：为了便于用解析法分析偏心车道荷载作用下考虑箱梁扭转和畸变翘曲应力影响的应力放大系数,基于薄壁箱梁约束扭转和畸变控制微分方程的初参数解,得到偏心车道荷载作用下简支箱梁同时考虑约束扭转和畸变翘曲内力的解析解,进一步得到相应翘曲应力。结合简支薄壁箱梁数值算例,分析偏心车道荷载作用下计入扭转和畸变翘曲应力后的总应力相对于弯曲应力的应力放大系数。研究结果表明:算例薄壁箱梁跨中截面腹板与底板交点处的正应力放大系数达到1.27,水平形心轴处腹板的剪应力放大系数达到2.21;针对畸变翘曲应力的计算结果表明:跨中截面腹板与底板交点处畸变翘曲正应力约为扭转翘曲正应力的5倍;畸变翘曲剪应力在薄壁箱梁底板、腹板及悬臂板内均较大。In order to analyze the stress amplification factor of thin walled box girders subjected to eccentric lane load considering torsion and distortion,based on the initial parameter solutions to the governed differential equations for constrained torsion and distortion,the analytic solution to the warping internal force of simply supported box girders was derived,and the relevant warping stress was further obtained.A simply supported thin walled box girder was adopted to analyze the stress amplification factor relative to bending stress by considering torsion and distortion warping stress.The results show that the mid span normal stress amplification factor at the intersection of web and bottom plates reaches 1.27,and the shear stress amplification factor for web plate at the horizontal centroid axis reaches 2.21.The calculation results for distortion and warping stress indicate that the distortion warping normal stress is about 5 times to the torsion warping stress at the intersection of web and bottom plates in mid span cross section.The distortion warping shear stress of thin walled box girders is all relatively large in the bottom plate,web and cantilever plate.

关 键 词：薄壁箱梁 约束扭转 畸变 应力放大系数 翘曲应力 

分 类 号：U448.213[建筑科学—桥梁与隧道工程]