Approximate Deflection Calculation of Variable Box Section Girder Considering the Effect of Shear Lag and Shear Deformation

摘要

Based on the equivalent stiffness and equivalent stiffness ratio method, an approximate method suitable for hand calculation is proposed to calculate the deflection of variable box section girder bearing load, in which, the double effects of shear lag and shear deformation can be taken into account. It shows that the deflection calculated by elementary beam theory without considering shear lag effect and the shear deformation is smaller, comparing to results calculated by the approximate method proposed in the paper. For such variable box sections girder, transverse shear deformation effect is greater than the shear lag effect when calculating the deflection. The approximate method offers a simple and effective calculating method for the design of box girder with variable cross section, in which, analysis formula can be applied in engineering practice through simple revision.