STUDY ON LOAD-SLIP CHARACTERISTIC CURVE OF PERFOBOND SHEAR CONNECTORS IN HYBRID STRUCTURES

The load-slip characteristics of shear connectors are the basis of simplified finite element analysis for hybrid structures. In order to investigate the shear transfer of perfobond strip connector (PBL) groups in hybrid structures, 24 groups of large-scale static PBL tests in three batches have been carried out with the assistance of distributed optic fiber sensors measurement techniques, based on which the mechanical mechanism and the important influencing factors for the load-slip relationship of PBL connectors are analyzed, and the corresponding formula on the ultimate bearing capacity of PBL connectors is proposed. According to the estimation method of population standard deviation and regression analysis, the load-slip characteristics of PBL connectors under elastic limit and ultimate limit states are generalized, while an expression of load-slip complete curve on PBL connectors under static loading is proposed. The results show that PBL connectors with perforated rebars in hybrid structures have higher ultimate bearing capacity and excellent ductility performance, while the perforated rebars have a significant effect on the load-slip characteristics of PBL connectors, and the shear-friction effect between perforated plates and surrounding concrete is an important component for the bearing capacity of PBL connectors. The elastic limit load and the yield limit load of PBL connectors is about 0.35 times and 0.695 times the ultimate limit load, respectively. The load-slip complete curve of PBL connectors consists of a straight line section in the elastic phase and a curve section following a logarithmic distribution in the nonlinear phase.