考虑竖向加劲肋作用的H形梁柱节点试验研究

Experimental study on H-shaped beam-to-column connections with vertical stiffener

针对我国现行钢结构设计规范对H形梁柱节点域厚度的要求未考虑竖向加劲肋作用,设计了2组4个平面中柱节点试件,进行拟静力试验,分析竖向加劲肋对节点破坏模式、承载力、刚度、延性、耗能能力等性能的影响。试验研究表明:试件滞回曲线形状稳定,节点域屈曲后曲线有捏拢现象,但承载力无明显下降,延性良好;竖向加劲肋对试件刚度、承载力和延性影响很小,但耗能能力增加、平面外变形减小、剪切屈曲性能明显改善,与具有相似节点域等效宽厚比的未设置加劲肋试件相比,延性相当,但耗能能力更好。根据研究结果提出了设置竖向加劲肋节点的等效宽厚比计算方法,建议将现行规范中节点域等效宽厚比不小于90的限值放宽到加劲节点域等效宽厚比不小于90。

Current provisions in design codes take no consideration of the effect of vertical stiffener on the requirements for panel zone thickness in H-shaped beam-to-column connections.Two series of four planar interior connections were designed as specimens for hysteresis experiment.The test aimed to study the influence of vertical stiffener on the performance of panel zone such as failure mode,strength,stiffness,ductility and energy dissipation characteristic.The results show stable hysteresis curves with slightly pinched phenomenon after the buckling of panel zone,but no obvious reduction in strength is observed and the ductility is desirable.The vertical stiffener brings limited impact on stiffness,strength and ductility.However,such reinforced specimens show increased energy dissipation capacity,reduced out-of-plane deformation and greatly improved shear buckling performance.The reinforced specimen exhibits similar ductility but increased energy dissipation capacity compared with identical specimen of equivalent width-to-thickness ratio without vertical stiffener.A formula to calculate this equivalent ratio for panel zone with vertical stiffener was also proposed and referred as reinforced equivalent width-to-thickness ratio.It is recommended to replace the current limitation of 90 for equivalent ratio by reinforced equivalent ratio in design provisions.