【摘要】 首先,选取余弦函数作为薄壁箱梁翼板剪滞翘曲位移函数,并在横截面的底板、顶板和悬臂板分别引入3个剪切转角最大差值函数,建立薄壁箱梁体系总势能表达式,进而根据变分原理推导出3个微分控制方程;然后,进一步对二阶常系数微分方程组进行求解,并以承受对称均布荷载的简支箱梁为算例,推导出薄壁箱梁任意横截面不同翼板处的法向弯曲应力σ_ix和无剪力滞效应时横向荷位e的计算方法;最后,采用有限元软件ANSYS建立对简支箱梁算例进行数值模型和分析,结果表明,按本文方法得到的截面弯曲应力结果与有限元数值解吻合度较高,验证了本文理论方法的可靠性。更多还原

【Abstract】 The cosine function was selected as the shear warp displacement function of thin-walled box girder, and three functions of maximum shear angular rotations were defined in the bottom plate, top plate and cantilever plate respectively. The total potential energy expression of thin-walled box girder system was established, and three differential governing equations were further derived according to the variational principle. By solving the second order differential equations with constant coefficients and taking a simply supported box girder under symmetrical uniformly distributed load as an calculating example, the expressions of bending normal stress σ_ix of flange slabs and lateral loading position e of box girder section without shear lag effect were derived. The finite element model of the calculating example was established and analysed by using ANSYS software. The results showed that the theoretical results of section bending stress obtained by the analysis method of this paper were in good agreement with the finite element numerical solution, and the reliability of this method was verified.更多还原