Study On Structural Behavior And Allowable Load Of Pbl Shear Connector Groups For Hybrid Structures On Serviceability Stage

Hybrid structures develop rapidly in recent years. As the core shear transfer components of hybrid structures, the steel-concrete joint sections are the key to combine the steel structure and reinforced concrete structure to work together. The rationality of these joint sections is directly related to the structural safety and durability. The perfobond rib shear connector (PBL), as a kind of general shear connectors, is very important in shear transfer system of steel-concrete joint sections, and it is worth further investigation.Under the support of National Natural Science Foundation of China (Grant No. 51178393), the serviceability limit state and the serviceability allowable load of PBL shear connector groups are studied. The main work and conclusions are listed below.(1) Relying on 18 model tests for PBL shear connector groups, their mechanical behavior during the whole loading process is studied. The results show that whole working process of PBL shear connector groups can be divided into pseudo-elastic stage, elastic-plastic stage, yielding hardening stage and decreasing failure stage. The yield situation is defined as the first row of PBL shear connector yields, and the serviceability limit state is defined as the pseudo-elastic limit state. The preliminary calculation method for the serviceability allowable load is proposed by the employment of load in pseudo-elastic limit stage. The influence factors of this load are also studied.(2) Based on 30 model tests for single-row PBL shear connector, the major influence factors of load-slip characteristics are analyzed. On the basis of the regression analysis, the load-slip curve function of the single-row PBL shear connectors before yielding is established. The equivalent linear stiffness of the single-row PBL is defined by referring to the definition of stud stiffness.(3) According to the theory of Goodman elastic interlayer and the mechanical properties of PBL shear connector groups in hybrid constructions, the simplified mechanical model for PBL shear connector groups is presented and the shear distributions of the PBL shear connector groups are deduced. Based on the definition of serviceability allowable load, the formula to calculate the serviceability allowable load is established. The results are acceptable by comparing the calculated value and experimental value.