Study On Failure Mode And Transfer Mechanism Of PBL Shear Connectors' Concrete Tenon

The performance of steel-concrete composite bridge is closely related to the shear connector of steel and concrete.Until now,the commonly used shear connector is PBL shear connector.PBL shear connector has better load-carrying capacity,stronger anti-fatigue performance and higher shear rigidity than conventional shear connector.Scholars have studied the mechanical properties of PBL shear connector by the Push-out test,but this method cannot observe the force part of the core in the concrete tenon damage process.Therefore,this research uses simulation method to analyze the stress state,failure-mode and load transfer characteristics of concrete tenon.Mainly include the following points:(1)This paper summarizes the test parameters and results of scholars ' at home and abroad,and analyses the main factors affecting failure-mode of PBL shear connectors' concrete tenon.(2)The paper sets the ratio of the thickness of the open steel plate to the aperture to a variable,and then builds 9 finite element models.(3)According to the variation trend of the concrete tenon,the equivalent stress characteristics and the principal stress state with increasing ratio of the thickness of the open steel plate to the aperture,the research analyzes the relationship between the ratio and failure-mode of PBL shear connectors' concrete tenon.(4)The results have shown that the failure modes of the concrete tenon are related to the ratio of the thickness of the open steel plate to the aperture;the concrete tenon in the hole bear pressure from the steel plate will spread pressure outward at the angle of 45 degrees;the best failure-mode of the PBL shear connector in the project should be shear failure-mode.The PBL shear connector has the best bearing capacity,the highest shear strength in elastic stage under the shear failure-mode.