预应力混凝土组合箱梁桥波形钢腹板的屈曲分析

BUCKLING ANALYSIS OF CORRUGATED STEEL WEBS IN PRESTRESSED CONCRETE COMPOSITE BOX-GIRDER BRIDGE

通过解析方法及空间有限元方法研究波形钢腹板预应力混凝土组合箱梁桥在各种腹板尺寸参数时,对钢腹板的剪切屈曲应力或临界荷载及屈曲模态的影响。计算及分析结果表明:腹板高度越大,其它参数不变时,屈曲临界荷载随折叠角度的增大而呈抛物线形的增加幅度越小;当腹板折叠角度越大,腹板越厚,其它参数不变时,屈曲临界荷载随着腹板高度的增加呈抛物线形的下降幅度越大。因此,在钢腹板的5个参数中,腹板高度及腹板折叠角度两个参数对腹板的剪切屈曲稳定和屈曲模态起着关键的作用,不能随意用腹板的高厚比来衡量屈曲应力的大小。

The influences of shear buckling stress, critical load and buckling mode of the corrugated steel webs with different web dimension parameters in prestressed concrete composite box-girder bridge are investigated by analytical method and 3D finite element method. The results show that when web heights increase and other parameters are kept constant, the rise level of buckling critical load in parabola shape will become less steep as web corrugation angles increase, and that when web corrugation angles and web thickness increase and other parameters are kept constant, the fall level of buckling critical load in parabola shape will become more steep as web heights increase. So the two parameters （web height and corrugation angle） in five parameters of web have a key role on shear buckling stability and web buckling mode, the buckling stress is not to be measured carelessly by ratio of height to thickness.