基于剪力滞效应研究箱型梁的附加弯矩和挠度

利用多项式建立箱型梁剪力滞效应分析的一维离散有限元模型,通过箱型梁翼缘板的纵向转角位移差函数建立附加弯矩和附加挠度计算公式,计算分析宽高比、宽跨比、高跨比等因子对箱型梁截面的附加弯矩和附加挠度的影响。结果表明,利用一维离散有限元法计算分析箱型梁附加弯矩和挠度的精度较高,结果可靠。箱型梁宽跨比或宽高比增大时,剪力滞效应所产生的附加弯矩对箱型梁的影响随之增大。箱型梁翼缘宽度对附加弯矩和附加挠度的影响较大,而箱型梁高度能够显著提高箱梁截面的抗弯刚度。

Analysis of Additional Bending Moment and Deflection of Boxgirders Based on Shear Lag Effect

Additional bending moment introduced by shear lag effect on box girders was analyzed based on the one-dimensional finite element method.The effects of the depth-span ratio,width-span ratio and width-depth ratio on deflection,bending moment and additional bending moment of box girders were investigated in details,respectively.The results obtained from one-dimensional finite element method agree well with those by close-form solutions,which show the effectiveness of the presented method.Examples demonstrate that the additional bending moment introduced by the shear lag effect on the box-girders increases with the widthspan ratio and the width-depth ratio.The flange-width of box-girder is greater impact on additional bending moment and additional deflection,but the depth can enhance the flexural rigidity.