2400型波形钢腹板抗剪性能分析

Analysis on shear behavior of type 2400 corrugated steel webs

随着波形钢腹板(corrugated steel webs,CSW)组合箱梁桥的发展,亟需针对适用于更大跨径的大尺寸CSW的力学性能进行研究。文章采用模型试验与有限元仿真相结合的方法,分析2400型大尺寸CSW的抗剪性能。首先通过一根2400型CSW工字钢梁的加载试验,掌握其基本受剪性能;然后通过3种加载方式下的有限元模型,对2400型CSW的屈曲稳定性和抗剪承载力进行分析;最后考虑腹板高度和厚度对2400型CSW弹性剪切屈曲性能的影响,并推导出弹性剪切屈曲强度优化公式。研究结果表明:2400型CSW的剪应变随荷载的增大而增大,并沿高度方向均匀分布,而靠近加载点处截面,当荷载超过400 kN后,剪应变分布呈现非均匀性;2400型CSW的屈曲荷载大于极限荷载,其抗剪承载力和屈曲稳定性均优于常规尺寸CSW;2400型CSW的高度和厚度都较小时易发生局部屈曲,高度和厚度都较大时易发生整体屈曲。该文提出的2400型CSW弹性剪切屈曲强度优化公式经验证具有较高的精度,可为工程设计提供一定的理论参考。

With the development of composite box girder bridge with corrugated steel webs(CSW),it is urgent to study the mechanical properties of large-size CSW for larger span.In this paper,the shear resistance of type 2400 large-size CSW is studied through the method of combining model test and finite element simulation.Firstly,its basic shear properties are obtained through the loading test of an I-beam with type 2400 CSW.Then,the buckling stability and shear capacity of type 2400 CSW are analyzed through the finite element simulation under three loading modes.Finally,the effects of webs height and thickness on the elastic shear buckling behavior of type 2400 CSW are considered.The results show that the shear strain of type 2400 CSW increases with the increase of load,and it is distributed evenly along the height direction.In the section near the loading point,when the load exceeds 400 kN,the shear strain distribution is non-uniform.The buckling load of type 2400 CSW is greater than the ultimate load.The shear capacity and buckling stability of type 2400 CSW are better than conventional-size CSW.Local buckling is easy to occur when the height and thickness of type 2400 CSW are smaller,and global buckling is easy to occur when the height and thickness are larger.The optimization formulas of elastic shear buckling strength of type 2400 CSW are verified to have high accuracy,and can provide theoretical reference for engineering design.