提出一种新型钢筋混凝土柱-钢梁(RCS)混合框架节点构造形式,通过对12个1/2比例的柱贯通型RCS混合节点低周往复加载试验,研究强节点系数ηj、节点核芯区加劲腹板构造、钢梁与节点连接构造等参数对试件破坏模式、滞回耗能特性和变形组成的影响。试验研究表明:随着强节点系数的减小,试件破坏形态由梁端的弯曲破坏转变为节点的剪切破坏;试件滞回曲线也相应的由耗能能力较好的梭型转变为捏拢的反S型。ηj〉1的试件梁端弯曲变形引起的层间位移超过总位移的60%,而ηj〈1的试件,层间位移主要由柱端弯曲变形引起。节点核芯区的加劲腹板有效提高了节点的抗剪强度和刚度,节点区的剪切变形对层间位移的贡献最大不超过10%。ηj〈1的试件,节点核芯区加劲腹板在1/20层间位移角时达到屈服,节点的受剪强度同时达到峰值,且随节点剪切变形的进一步增加无明显衰减。节点核芯区预埋高强螺栓和钢梁的连接构造合理可靠,加载过程中无明显相对变形,可满足梁柱刚性节点假设。成果可供装配式RCS混合结构的工程设计参考。
Abstract: A new type of RC column-steel beam(RCS) hybrid joints was proposed and twelve half scale through-column- type RCS hybrid joints were tested under cyclic loads to investigate the effect laws of strong joint coefficient ηj, details of steel web plate, connection details between steel beams and joint core to the failure modes, hysteretic performance and energy dissipation capacity of specimens. It is indicated that with the decrease of strong joint coefficient ηj, the failure modes of specimens converted from flexural failure of steel beams, which induced a good energy dissipation capacity of specimens with hysteretic loops of plump shape, into shear failure of joint core, which induced a poor energy dissipation capacity with hysteretic loops of inverse "S" shape. For specimens with ηj 〉 1, more than 60% of the story drift was caused by the flexural deformation of beams, while the flexural deformation of columns made the main contribution to the story drift for specimens with ηj 〈 1. The shear strength and stiffness are remarkably enhanced due to the presence of the encased steel web plate and the story drift caused by shear deformation of joint core is less than 10% of the total story drift. The maximum shear strength can be achieved when the encased steel web plate yields at the story angle of 1/20, for specimens with ηj〈 1, and shows no obvious degradation with the increase of shear deformation of joint core. Connections of steel beam and joint core using embedded high-strength bolts are valid and no obvious separation deformation is observed during testing. This paper can provide reference for the engineering practice of prefabricated RCS hybrid structures.