考虑全截面剪切变形效应的波形钢腹板箱梁挠度计算

Calculation of Deflection of Box Girder with Corrugated Steel Webs Considering Shear Deformation Effect of Whole Section

为了分析计算波形钢腹板箱梁在竖向荷载作用下的弯曲挠度,考虑波形钢腹板和混凝土顶、底板在其自身平面内的全截面剪切变形,引入符合力学规律的波形钢腹板和混凝土顶、底板在其面内剪切变形的位移函数,利用能量变分原理,推导出波形钢腹板箱梁挠度计算的解析解。结合单箱单室和单箱双室波形钢腹板箱梁算例,与仅考虑波形钢腹板剪切变形的挠度计算方法和ANSYS有限元解进行了比较分析。结果表明:该解析解的计算结果比仅考虑波形钢腹板剪切变形的计算结果更加精确,与有限元分析结果吻合良好,误差在5%以内,满足挠度计算的精度需求,且跨径越小,全截面剪切变形效应对挠度的影响越明显;针对单箱单室波形钢腹板箱梁,全截面剪切变形效应对挠度的贡献最大为36. 12%,其中波形钢腹板的剪切变形对总挠度的贡献最大为34. 46%,剪力滞效应对总挠度的贡献最大为1. 66%;而对于单箱双室波形钢腹板箱梁,全截面剪切变形效应对挠度的贡献最大为40. 91%,其中波形钢腹板的剪切变形对总挠度的贡献最大为36. 03%,剪力滞效应对总挠度的贡献最大为4. 88%;在相同的工况下,波形钢腹板箱梁的箱室越多,全截面剪切变形效应对挠度的贡献越大,挠度贡献值的最大增幅为4. 79%,在不同的工况下,集中荷载作用下全截面的剪切变形效应较为明显。

In order to analyze and calculate the bending deflection of box girder with corrugated steel webs under vertical loads,considering the whole sectional shear deformation of corrugated steel web,concrete roof and floor in their own planes,introducing the displacement functions of shear deformation of corrugated steel webs,concrete roof and floor in their own planes agreeing with the mechanical laws,an analytical solution of the deflection of box girder with corrugated steel webs is derived using the energy variation principle. For the cases of sing-box single-cell and sing-box double-cell box girders,the analytical solution is compared with that of the deflection calculation values which only considers the shear deformation of corrugated steel webs and that of the finite element values of ANSYS. The result shows that( 1) The analytical solution is moreaccurate than that only considering the shear deformation of corrugated steel webs,and the analytical solution is close to the result of finite element analysis. The error is less than 5%,which satisfies the accuracy requirement of deflection calculation. The smaller the span is,the more obvious the influence of the whole section shear deformation effect on the deflection is.( 2) In the case of sing-box single-cell box girder,the maximum contribution of the shear deformation effect of the whole section to the deflection is 36. 12%,of which the maximum contribution of shear deformation of corrugated steel webs to the total deflection is34. 46%,and the maximum contribution of shear lag effect to the total deflection is 1. 66%.( 3) As for sing-box double-cell box girder with corrugated steel webs,the maximum contribution of the shear deformation effect of the whole section to the deflection is 40. 91%,of which the maximum contribution of shear deformation of corrugated steel webs to the total deflection is 36. 03%,and the maximum contribution of shear lag effect to the total deflection is 4. 88%.( 4) Under the same conditions,the more the cells of box girder with corrugated steel webs,the greater the contribution of the shear deformation effect of the whole section to the deflection,and the maximum increase of the contribution value of the deflection is 4. 79%.Under different conditions,the shear deformation effect of the whole section under concentrated load is more obvious.