基于修正翘曲位移函数的单箱双室薄壁箱梁剪力滞效应分析  

Analysis on shear lag effect in thin-walled box girder with single-box two-cell based on modified warping displacement function

作　　者：郭向荣[1] 张文格 崔睿博 李夏元[2] 邹欣杭 GUO Xiangrong;ZHANG Wenge;CUI Ruibo;LI Xiayuan;ZOU Xinhang(School of Civil Engineering,Central South University,Changsha 410075,China;School of Transportation,Southeast University,Nanjing 211189,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]东南大学交通学院,江苏南京211189

出　　处：《铁道科学与工程学报》2024年第12期5117-5127,共11页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(U1934207)。

摘　　要：为完善单箱双室薄壁箱梁剪力滞效应理论研究,基于弯曲剪力流零点位置分布确定翼缘板宽度划分原则,考虑剪切变形对弯曲曲率的影响,引入内力平衡因子,利用纵向翘曲位移横向分布连续性条件,对翼缘板纵向翘曲位移函数进行修正。同时,考虑悬臂翼缘板端部自由状态,提出初始剪切转角的概念,以解释悬臂板端部理论应力高于真实应力的现象,并明确初始剪切转角对纵向翘曲位移函数的影响机理。采用无量纲法,统一翼缘板纵向翘曲位移滞后函数的关系,理论推导纵向翘曲位移横向分布函数的合理形式。基于能量变分原理,建立单箱双室薄壁箱梁剪力滞效应控制微分方程,并给出位移边界条件。以单箱双室薄壁简支箱梁满布均布荷载为例,采用本文提出的分析方法对算例进行理论求解,并利用ABAQUS有限元软件建立相应的力学模型,将本文理论解析解与有限元数值结果进行比较分析。研究结果表明:根据弯曲剪力流零点位置确定单箱双室薄壁箱梁剪力滞效应翼缘板宽度划分是合理可行的。本文理论分析方法(考虑初始剪切转角和翼缘板应力修正)计算的翼缘板应力和挠度值与有限元数值结果吻合良好,最大误差不超过2%,不仅验证了选用余弦函数作为纵向翘曲位移横向分布函数的合理性,还表明了理论分析方法和理论推导的正确性。To enhance the theoretical investigation of the shear lag phenomenon in thin-walled box girders with a single-box two-cell configuration,principles governing the division of flange plate widths were established based on the distribution of zero points in the bending shear flow.Consideration was given to the impact of shear deformation on bending curvature,with the introduction of an internal force balance factor.The longitudinal warping function of the flange plates was modified by leveraging the continuity conditions of longitudinal warping displacement distribution.Additionally,the free-state condition of cantilevered flange plate ends was addressed,and the concept of initial shear rotation angle was proposed to explain the phenomenon that the theoretical stress at the end of cantilever plate is higher than the real stress,and to elucidate the influence of initial shear rotation angle on the longitudinal warping function.By utilizing a dimensionless approach,the relationship of the longitudinal warping function of the flange plates was standardized,and a reasonable formulation of the transverse distribution function of longitudinal displacement was derived theoretically.By employing the principle of energy variation,a differential equation governing the shear lag effect in thin-walled box girders with a single-box two-cell configuration was formulated,alongside provision of displacement boundary conditions.An illustrative example involving a fully loaded uniformly distributed load on a simply supported thin-walled box girder with a single-box two-cell configuration was utilized to obtain theoretical solutions using the analytical method proposed herein.Furthermore,a corresponding mechanical model was developed using ABAQUS finite element software to compare and analyze theoretical analytical solutions with finite element numerical results.The findings confirm the rationality and feasibility of determining flange plate width division for the shear lag effect in thin-walled box girders with a single-box two-cell

关 键 词：薄壁箱梁 单箱双室 剪力滞效应 弯曲剪力流零点 初始剪切转角 

分 类 号：U448.213[建筑科学—桥梁与隧道工程]