通过7组21个PBL剪力键(开孔钢板连接件)试件的推出试验,研究PBL剪力键的弹性承载力、极限承载力、滑移量及延性系数等静载力学性能。运用推出试验的非线性有限元仿真分析,研究PBL剪力键的传力和破坏过程。结果表明:PBL剪力键的极限承载力高,延性系数大;按照荷载-滑移曲线及内部应力状态,PBL剪力键的破坏过程可分为线性阶段、弹性阶段及塑性阶段;弹性阶段之前承载力主要由孔洞内混凝土提供,弹性阶段之后承载力主要由贯穿钢筋提供。由于PBL剪力键的力学性能指标尚无明确的定义和标准化的推出试验方法,使得各试验者得到的PBL剪力键承载力回归公式没有普适性。为使PBL键得到更广泛的应用,应尽快规范PBL键推出试验方法。
Push-out test is adopted to investigate the mechanical characteristics of 21 specimens in 7 types PBL(prefobond rib) shear connectors,such as elastic bearing capacity,ultimate bearing capacity,slippage and ductility factor.With the introduction of nonlinear finite element method simulation of push-out test,the load transfer mechanism and failure process of PBL shear connectors' has been analyzed.The conclusions show that PBL has excellent bearing capacity and good ductility.According to the load-slippage curve and inner stress state,the failure process of PBL can be divided into 3 stages: linear stage,elastic stage and plastic stage.The bearing capacity before the elastic stage is mainly provided by concrete and the rebar contributes more to the bearing capacity of the post-elastic stage.Due to the lack of clear definitions of PBL shear connectors' performance index and standardized push-out test method,the calculation formula of PBL's bearing capacity proposed by researchers are not universal.For the more widely use of PBL shear connector,the standardization of push-out test needs further research.