薄壁曲线箱梁考虑材料弹塑性的剪力滞效应

依据势能变分原理,推导了薄壁曲线箱梁考虑翼缘应力剪力滞效应和材料非线性的刚度矩阵。采用样条有限点法和截面内力塑性系数法对薄壁曲线箱梁的弹塑性问题进行了求解。研究表明:弯曲剪力滞效应系数的非线性特征较挠度和扭转角的要明显;在荷载达到一定程度时,随荷载的增加,箱梁截面上的翼缘应力的分布逐渐均匀。该文的方法简单、实用,并可推广于变截面、变曲率薄壁曲线箱梁的计算。

SHEAR LAG EFFECT FOR THIN-WAILED CURVED BOX GIRDER IN CONSIDERING ELASTICS AND PLASTICS OF MATERIALS

By mean of potential variational principles, the stiffness matrix of thin-walled curved box girders in considering the shear lag effect of flange’s stress and material nonlinearity is obtained. The elastic and plastic problem of thin-walled curved box girders is solved with the spline finite point method and the section internal force plastics coefficient method. The research shows that the nonlinear property of the moment shear lag coefficient is more obvious than that of the displacement and torsion; when the load reaches certain values, the distribution of flange’s stresses in the section of box girders become more and more uniform with the increasing of the load. The proposed method is simple, practical and could be also used to calculate thin-walled curved box girders with the varying section and varying curvature.