| With the rapid development of social economy,the application of steel concrete composite structures in the field of infrastructure is becoming increasingly widespread due to their excellent mechanical performance.The extensive application of steel-concrete composite structure bridges has promoted the research of shear connectors in key loadbearing parts of composite structures.Among them,the shear performance of perforated steel plate shear keys is good,which has received widespread attention.The research results are quite abundant,but due to the many factors affecting the parameters of perforated steel plate shear keys,the universality of current research results is not high,and the mechanical evaluation standards are not unified.Currently,research on shear keys is mostly based on static loads and cannot fully reflect the mechanical performance of shear keys.This article conducts research on the mechanical response of perforated plate shear keys under dynamic and static loads,and based on the research results,takes an actual corrugated steel web composite bridge as an example to design and calculate the shear keys.Through the summary and analysis of typical pushout tests of perforated plate shear connectors,the shear keys of the perforated plate were divided into two categories for research,and the bearing mechanism,failure mode,and corresponding bearing capacity calculation formulas of the two types of perforated steel plate shear keys were obtained.And the ultimate bearing capacity state of the shear key was established by considering safety reserves,deformation requirements,and reasonable failure modes.Through three-dimensional nonlinear numerical simulation method,finite element analysis was conducted on two types of perforated plate shear keys under static load,and the bearing capacity formulas of the two types of perforated plate shear connectors were determined.Analyzed the factors affecting the mechanical properties of shear keys under static loads,and found that the depth of embedding of shear keys in concrete structures has a significant impact;The concrete strength has been increased to 1.67 times the original value.For composite specimens,the ultimate bearing capacity has been increased to 1.3 times the original value.For embedded specimens,the ultimate bearing capacity has been increased to1.34 times the original value;From the bearing mechanism,it can be seen that for composite specimens,the penetration of steel bars has a significant impact on the bearing capacity,while for embedded specimens,the diameter of the penetration of steel bars increases to 1.56 times the original,and the bearing capacity increases to 1.63 times and 1.58 times the original,respectively;For the study of selecting pore sizes of 40,50,and 60 mm for the opening diameter,the bearing capacity of the composite shear key was increased by 6% and 7%,respectively.The mechanical behavior of shear keys under static load was described using three stages,and the entire failure process was studied.Simulate the drop hammer impact of two types of shear keys through a simplified experimental model,and obtain the failure forms,ultimate bearing capacity,and changes in structural internal forces of each specimen.Exploring the factors affecting the bearing capacity of shear connectors under dynamic loads,the concrete strength was increased by1.67 times,the ultimate bearing capacity of composite specimens was increased by 1.21 times,and the bearing capacity of embedded specimens was increased by 1.34 times;The diameter of the through steel bar has been increased by 1.56 times,and the bearing capacity of the composite specimen has been increased by 1.6 times.The embedded specimen has been increased by 1.58 times,1.73 times,and 1.69 times,respectively;For the study of selecting pore sizes of 40,50,and 60 mm for the opening diameter,the load-bearing capacity of the composite specimen increased by 3%.Based on the simulated data,two calculation formulas for the dynamic load of shear keys were proposed,and it was found that the fitting effect was good. |
