翼板变厚度箱形梁的剪力滞效应分析

针对翼板厚度沿截面宽度方向线性变化的混凝土箱形梁,利用势能变分原理对其进行剪力滞效应分析.选取剪力滞效应引起的附加挠度作为描述剪力滞变形状态的广义位移,并考虑轴力平衡条件对剪力滞效应的影响.将简支箱梁在均布荷载和集中荷载作用下的理论计算值与有限元值进行对比,结果表明:采用该文分析方法得到的计算值与有限元值吻合良好,证实了该文分析方法的正确性.与将翼板变厚度箱梁简化为等厚度箱梁的计算方法相比,考虑翼板厚度变化的计算方法可提高计算精度,误差减小量最大达到了5.65%.

Analysis of Shear Lag Effects in Box Girders With Variable-Thickness Flanges

For concrete box girders with flanges of linearly variable thicknesses along the cross section widths, shear lag effects were analyzed according to the potential energy variation principle. The additional deflection caused by the shear lag effect was used as the generalized displacement to describe the shear lag deformation state, in view of the influence of the axial force equilibrium condition on the shear lag. The calculation results of several simply supported box girders subjected to uniform loads and concentrated loads were compared. The results show that, the proposed method gives stresses in good agreement with those obtained from the finite element method, which confirms the correctness of this method. Compared with the simplified calculation method for box girders with equivalent uniform thickness flanges, this method has enhanced accuracy for real box girders with variable thickness flanges, and the error reduction is up to 5.65%.