槽型宽翼梁剪滞效应分析的有限段法

针对槽型宽翼梁剪滞效应分析已有方法通常忽略横向剪切变形的影响、计算工作量大、不便于工程应用的局限性,提出一种能准确分析变截面槽型宽翼梁剪滞、剪切双重效应的有限段法。基于最小势能原理,建立了槽型宽翼梁考虑剪滞效应和剪切变形双重影响的平衡控制微分方程及自然边界条件。在由方程得出均布荷载作用下的内力和位移初参数解的基础上,导出了槽型宽翼梁的有限段单元刚度矩阵和等效节点荷载列阵。应用有限段法,结合有机玻璃模型梁试验,分析了槽型宽翼梁竖向位移和应力的横向分布规律。数值算例表明,有限段法计算结果与有机玻璃模型试验实测结果以及ANSYS解符合良好;槽型宽翼梁的剪力滞效应明显;在槽型宽翼梁桥的设计与施工控制中,必须充分考虑剪力滞效应和剪切变形对结构应力和位移的影响。

Finite Segment Method for Wide-flange Beam Considering Both Shear Lag and Shear Deformation

Dealing with the limitation of existential studies on shear lag effect of wide-flange beam which did not consider its shear deformation commonly and in which the calculation workload was heavy,finite segment method for the analysis of both shear lag and shear deformation for general wide-flange beam with a non-uniform cross-section in bridge engineering was presented.Based on the minimum potential energy principle,the differential equations and their boundary conditions considering both shear lag and shear deformation of wide-flange beam were established,and the finite segment element stiffness matrix and its equivalent nodal forces based on the initial-value solutions to internal forces and deflections of the element by the equations under a uniformly distributed load were derived.The method was applied to investigate stress transverse distribution and vertical deflection of plexiglass wide-flange beam model.The numerical calculation results are compared with those from the plexiglass model test and ANSYS,which show that the convenience and accuracy of the proposed method.The results also indicate that shear lag effect of wide-flange beam is evident and the influence of shear lag and shear deformation upon the stress transverse distributions and vertical deflection of the wide-flange beam should be taken into account in the bridge design and construction control process.