单箱三室箱梁的剪力滞翘曲位移模式研究

针对等截面单箱三室箱梁的空间变形特点，并考虑梁纵向平衡所附加的全截面纵向位移．假设4种不同的箱梁剪力滞翘曲位移模式；基于最小势能原理推导出系统的总势能函数，由变分法得到一组带有边界条件的微分方程，据此推导出不同的剪力滞翘曲函数下的剪力滞系数的分布情况；列举算例并借助有限单元法验证各种翘曲位移函数得到的剪力滞系数．最后将本文解与有限元算出的剪力滞系数比较，分析各种剪力滞翘曲位移模式的适用性；并与不考虑梁纵向平衡所附加的全截面纵向位移算出的剪力滞系数进行比较。

Study for shear lag warping displacement mode in box girder with single box triple cells

Aiming at the space deformation characteristics of box ~Hrder with constant section single box triple cells, and considering the attached total cross section of the longitudinal displacement on longitudinal balance beam,4 types of box girder shear lag warping displacement mode are assumpted. The total potential energy function of system is deduced based on the principle of minimum potential energy, obtaining a set of differential equations with boundary conditions by the variational method, based on it, deduced the distributed situation of the shear lag coefficient in different warping displacement functiont. By means of some examples and by using the finite element method, verificated the shear lag coefficient of various warping displacement function. At last, the solution of this paper was compared with the shear lag coefficient of the finite element analysis. Analyzed different kinds of the shear lag coefficient of warping displacement mode that got close to the finite element method. And compared with the shear lag coefficient of considering the attached total cross section of the longitudinal displacement on longitudinal balance beam.