考虑次生剪切变形的带隔板偏轨钢箱梁位移应力解

Solutions for Displacements and Stress of Off-Track Steel Box Girder Strengthened by Diaphragms Under Secondary Shear Deformation

为研究简支带隔板偏轨钢箱梁的变形及受力特性,将带隔板钢箱梁视为具有内部赘余联系的高次超静定结构,提出考虑截面次生剪切变形的畸变柔度法,并运用精细时程积分迭代算法提高柔度方程求解精度.然后基于叠加原理,给出简支带隔板钢箱梁考虑剪力滞效应的弯曲位移及应力解析解、扭转翘曲函数解析解和考虑畸变剪切变形的畸变初参数法,最终得到偏载作用下箱梁位移及应力解析解.结果表明:隔板位置对畸变横纵向位移影响显著,对弯曲及扭转横纵向位移影响微弱;同时隔板可有效提高箱梁抗畸变框架刚度,大幅减小由畸变产生的截面横向挠曲变形.

In order to investigate the deformation and mechanic property of the off-track simply supported steel boxgirder strengthened by diaphragms,by regarding the box-girder with diaphragms as a high-order statically-indeterminate structure of inner redundant connections,a distortional flexible method considering the secondary shear deformation of cross-section is proposed,and the iterative algorithm based on the precise time-integration method is adopted to improve the accuracy of the flexibility equation. Then,based on the superimposition principle,the solutions for the flexural displacement and stress of the simply supported steel box-girder with diaphragms are both obtained with the shear lag effect being considered,and the solutions for torsional warping functions is deduced. Moreover,an initial parameter method of distortion is put forward by taking into account the shear deformation. Finally,the analytical solutions for the displacements and stress of the box-girders under offset load are obtained. The results show that the position of diaphragms has a significant influence on the longitudinal and transversal distortional displacements but with only a little influence on the flexural and torsional displacements,and that the diaphragms can effectively increase the distortional frame rigidity of box girders and greatly reduce the transversal flexural deformations caused by the cross-sectional distortion.