考虑波形腹板剪切的端部固支组合梁挠度分析

Analysis on the deflection of fixed composite beam with corrugated steel webs considering the effect of shear deformation

波形钢腹板组合梁因其优良性能得到广泛应用,其挠度问题是研究的重点之一,近年来我国对波形钢腹板组合梁挠度计算方法的研究虽有长足的进步,但多集中于静定结构,并且端部固支的超静定结构体系在桥梁工程中应用广泛。为了探讨不同支承下波形钢腹板组合梁滑移附加挠度变化的规律,并为波形钢腹板组合梁的后续研究提供理论基础和参考,在足够刚度的前提下将端部固支波形钢腹板梁简化为两端固支和一端固支一端活动铰支的端部约束条件,推导了其考虑滑移和腹板剪切变形影响时的跨中挠度计算公式,找到适用于实际桥型的挠度计算方法;基于试验梁和有限元模型对本文公式进行了验证,结果表明:端部固支波形钢腹板组合梁的滑移附加挠度占比随剪切刚度的变化趋势显著区别于一端固定铰支一端活动铰支的抛物线型而呈线性变化;不对称约束放大了波形钢腹板组合梁腹板的剪切变形和滑移效应。

Composite beam with corrugated steel webs are widely used because of their excellent properties.Although the research on deflection calculation of composite beam with corrugated steel webs which is one of the focuses of its research in China has made great progress in recent years,but only statically determinate structures are considered,and the widely use of statically indeterminate structures with fixed ends in bridge engineering.In order to discuss the deflection of fixed composite beam with corrugated steel webs and provide theoretical basis and guidance for follow-up study,this paper assumes that joint stiffness is large enough,the composite beam with corrugated steel webs will be simplified as two fixed ends or one end fixed and the other hinged,considering the influence of slip and web shear deformation,the corresponding formula of midspan deflection is derived.It is hoped that the deflection calculation method suitable for the actual bridge type will be found step by step.Based on test beam and finite element model,the formula in this paper is verified.The results show that:the proportion of additional slip deflection of composite beams with corrugated steel webs fixed at the ends varies linearly with shear stiffness,which is significantly different from that of parabolic pattern of beams with simply supported ends.The asymmetrical support magnifies the shear deformation and slip effect of composite beams with corrugated steel webs.