单箱多室波形钢腹板组合箱梁约束扭转剪应力分析  

Analysis on Shear Stress of Single-box Multi-cell Composite Box Girders with Corrugated Steel Webs under Restrained

作　　者：黄洪猛 张元海[1] 罗奎 HUANG Hongmeng;ZHANG Yuanhai;LUO Kui(College of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;College of Civil Engineering,Northwest Minzu University,Lanzhou 730030,China;College of Civil Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070 [2]西北民族大学土木工程学院,甘肃兰州730030 [3]湖南大学土木工程学院,湖南长沙410082

出　　处：《湖南大学学报（自然科学版）》2023年第9期186-194,共9页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(51968040);中央高校基本科研业务费专项资金项目资助(31920230179)。

摘　　要：波形钢腹板组合箱梁扭转刚度小、截面易发生翘曲变形.为合理计算单箱多室波形钢腹板组合箱梁约束扭转时的剪应力,对剪力流进行分解,根据剪力流的传递路径、微元体纵向平衡及翘曲位移连续性,引入能够反映各室箱壁剪力流传递规律的常数,考虑波形钢腹板的褶皱效应推演出截面几何特性和剪应力的实用计算公式.基于Reissner原理建立约束扭转控制微分方程,并用初参数法求得解析解.用该文解析法和ANSYS有限元法计算偏心荷载作用下简支箱梁的扭转剪应力,并引入反映扭转剪应力对总剪应力影响的剪应力增大系数和翘曲剪应力对扭转剪应力贡献的剪应力系数,详细分析了梁宽和箱室数量对剪应力的影响.研究结果表明:该文解析解与ANSYS有限元解吻合良好;梁宽增大和箱室数量增加均可降低扭转剪应力;约束扭转使得外腹板剪应力增大系数达到1.69,且腹板间的总剪应力表现出明显的分布不均匀性;翘曲剪应力对扭转剪应力的影响显著,设计时不可忽略;设计时应考虑混凝土顶底板扭转剪应力对主拉应力的影响,避免斜裂缝的产生.Composite box girder with corrugated steel webs has small torsional stiffness and is easy to produce warping deformation.To reasonably calculate the shear stress of single-box multi-cell composite box girders with corrugated steel webs under restrained torsion,the shear flow was decomposed,and constants that can reflect the shear flow transfer mechanism of each cell box wall were introduced based on the shear flow transfer path,longitudinal equilibrium of differential bodies and warping displacement continuity.The practical formulas for section geometrical property and shear stress considering the folding effect of corrugated steel web were deduced.The governing differential equation for analyzing restrained torsion was established based on Reissner’s principle,and an analytical solution was obtained by employing the initial parameter method.The torsional shear stress of the simply supported box girder under an eccentric loading was calculated by the present analytical method and ANSYS finite element method.The shear stress increment coefficient reflecting the effect of torsional shear stress on total shear stress and the shear stress coefficient reflecting the contribution degree of the warping shear stress to the total shear stress were introduced.The influences of girder width and cell number on the shear stress were analyzed.The results show that the present analytical solution agrees well with ANSYS finite element solution.The increase in girder width and cell number can reduce torsional shear stress.The shear stress increment coefficient of the outside web under restrained torsion reaches 1.69,and the total shear stress distribution between webs shows obviously uneven.The influence of warping shear stress on torsional shear stress can’t be ignored.The effect of torsional shear stress on principal tensile stress in the top and bottom concrete slab should be considered in the design to avoid oblique cracks.

关 键 词：组合箱梁 波形钢腹板 约束扭转 单箱多室 剪力流 Reissner原理 剪应力 

分 类 号：U448.213[建筑科学—桥梁与隧道工程]