部分充填混凝土窄幅钢箱连续组合梁负弯矩区局部屈曲分析与试验研究

Analysis and experimental study on local buckling behavior of negative bending region of partial-concrete-filled narrow-width steel box continuous composite beams

部分充填混凝土窄幅钢箱连续组合梁主要由钢筋混凝土翼板、下箱室充填混凝土的窄幅钢箱梁和抗剪连接件组成。通过2根部分充填混凝土窄幅钢箱组合梁弯曲性能试验研究,对比考察了部分充填混凝土窄幅钢箱连续组合梁负弯矩区的受力全过程,分析了组合梁钢板的局部屈曲特征,给出了钢梁腹板屈曲应力的简化计算模型。试验结果表明,钢箱内部分充填混凝土可以有效地提高负弯矩区的抗弯性能、梁的整体延性性能和受压区钢梁的稳定性,能够显著地改善钢板的局部屈曲性能。

The partial-concrete-filled narrow-width steel box continuous composite beams is composed of the slab of reinforced concrete flange plate,narrow-width steel box beam with concrete filled in lower box and some shear connectors.Experimental research on bending performance of two partial-concrete-filled narrow-width steel box composite beams was carried out. The entire mechanical processes of negative moment regions of the partial-concrete-filled narrow-width steel box continuous composite beams were compared and investigated. The characteristics of local buckling of the composite beams＇ steel plates were analyzed. A simplified calculation model of buckling stress for steel beams web was given. The experimental results show that steel box with partial-filled concrete can effectively improve the bending performance of the negative bending moment region,the overall ductility of the beams and stability of the steel beams in compression zone,and can significantly improve the performance of local buckling of the steel plate.