Shear Resistance Assessment of the Y-Type Perfobond Rib Shear Connector under Repeated Loadings

Abstract

The steel–concrete composite structures consist of two different material parts, which are connected with reliable shear connectors to enable the combined action of the steel and concrete members. The shear connectors may experience either one-directional repeated cyclic loadings or fully reversed cyclic loadings depending on the structural functions and acting loadings. It is essential for structural engineers to estimate the residual shear strength of the shear connectors after action of repeated loads. The characteristics of deteriorating shear capacities of Y-type perfobond rib shear connectors under repeated loads were investigated to estimate the energy dissipating capacity as well as the residual shear strength after repeated loads. To perform the repeated load experiments four different intensities of repeated loads were selected based on the monotonic push-out tests which were performed with 15 specimens with five different design variables. The selected load levels range from 35% to 65% of the representative ultimate shear strength under the monotonic load. In total, 12 specimens were tested under five different repeated load types which were applied to observe the energy dissipating characteristics under various load intensities. It was found that the dissipated energy per cycle becomes stable and converges with the increasing number of cycles. A design formula to estimate the residual shear strength after the repeated loads was proposed, which is based on the residual shear strength factor and the nominal ultimate shear strength of the fresh Y-type perfobond rib shear connectors. The design residual shear strength was computed from the number of repeated loads and the energy dissipation amount per cycle. The reduction factor for the design residual shear strength was also proposed considering the target reliability level. The various reduction factors for the design residual shear strength were derived based on the probabilistic characteristics of the residual shear strength as well as the energy dissipation due to repeated loads.

Study on Shear Resistance Property of a New PBL Connector with Steel–Rubber Tenon

“…Several scholars, including Vianna, Li, Zheng, Lin and Wang et al, analyzed the damage mode of the connector as well as the load–slip relationship by controlling each influencing parameter’s variable based on push-out tests and numerical simulations [ 3 , 26 , 27 , 28 , 29 ], while studying the shear resistance of PBL connectors as well. Suzuki and Kim et al considered the state of the shear connector subjected to repeated loading in the actual operation and studied it through extensive push-out tests and numerical simulations, and found that the PBL connector was superior to the conventional pinned connector under this loading condition, and proposed their design of residual shear strength discount factors and design equations for the shear strength under cyclic loading [ 30 , 31 , 32 ]. Through the study of PBL connectors by many scholars, it can be found that the calculation method of shear capacity is a key point for evaluating the shear performance of PBL connectors, and the calculation method of shear capacity can be deduced by the combination of numerical simulations and parameter analyses.…”