中文摘要：

为精确分析薄壁箱梁的剪力滞效应,从箱梁各翼缘板的面内剪切变形与纵向位移关系出发,推导剪力滞翘曲位移函数的基本表达式。考虑剪力滞翘曲应力的轴向自平衡条件,对剪力滞翘曲位移函数进行修正,以便得到适用于带悬臂板箱梁的合理翘曲位移函数。对剪力滞效应引起的截面形心轴与中性轴之间的偏离进行了论证。详细分析剪力滞翘曲位移函数修正项及箱梁高宽比、宽跨比、板宽比等参数对剪力滞翘曲应力的影响。结果表明：推导的剪力滞翘曲位移函数计算的简支箱梁跨中截面应力值与实测值及有限元计算结果吻合良好;高宽比的影响较小,宽跨比和板宽比的影响较大;当板宽比达到1.5时,翘曲位移函数修正项对翘曲应力的影响达到18%。

英文摘要：

In order to accurately analyze shear-lag effect of thin-walled box girder,fundamental expression of the shear-lag warping displacement function was derived from the relationship between in-plane shear deformation and longitudinal displacement of flanges.Considering the axial self-equilibrium condition for shear-lag warping stress,the shear-lag warping displacement function was modified to be suitable for box girders with cantilever plates.The deviation between centroidal axis and neutral axis of cross section due to shear-lag effect was demonstrated.The influences of the modified term of shear-lag warping displacement function and the ratios of depth to width,width to span and the cantilever plate width to top plate width on the warping stress were analyzed in detail.The results show that the stresses at the mid-span cross section of simply-supported box girder calculated by shear-lag warping displacement function are in good agreement with test results and those by finite element method.The effect of the depth to width ratio is relatively small while those of the width to span ratio and the cantilever plate width to top plate width ratio are much larger.The effect of the modified term of shear-lag warping displacement function on warping stress reaches 18% when the plate width ratio is 1.5.