非线性温度梯度下悬臂箱梁的剪力滞效应

摘要

为分析箱梁截面沿高度方向非线性温度梯度下的自应力,文章提出了双参数函数用于计算梁翼板纵向位移,该函数的2个参数可考虑温度自应力中剪力滞效应引起的上、下翼板剪切转角最大差幅值的差别;基于最小势能原理建立了计算箱梁温度自应力的偏微分方程组和边界条件,并求解了悬臂梁下微分方程的解.算例分析结果表明,双参数函数所得梁翼板的位移和应力分布计算结果与有限元计算结果吻合较好.%In order to analyze the self-equilibrating stresses of box girder induced by the nonlinear tem-perature gradient along with the height,a double parameters function is proposed to estimate the spanwise displacement.The double parameters can be used to estimate the amplitude discrepancy of maximum difference of angular rotation of top and bottom flanges caused by the shear lag effect of the self-equilibrating thermal stresses.Then,based on minimum potential energy principle,a set of par-tial differential equations and boundary conditions governing the self-equilibrating thermal stresses are formulated.An analytic solution for the temperature lag shear effect on cantilever box girder is ob-tained.The numerical results show that the stresses and displacements of flanges obtained by the double parameters method agree well with the results of finite element method.