Research On Shear Behavior Of Stud Shear Connectors Under Polar Low Temperature

With the development of science and technology,the application of steel-concrete composite structures keep increasing.The steel-concrete composite structures play an important role in polar resource exploitation and the infrastructure construction in western and northeastern China.The studs,a kind of shear connectors,ensure the safety and coordination of concrete and steel in steel-concrete composite structures.In order to investigate the shear behavior of studs under polar temperature,22 push-out specimens were prepared.The equipment included large-scale cold storage,insulation box and pressure testing machine.The investigated parameters are temperatures,stud diameters,length to diameter ratios and concrete strengths.The load-slip and load-strain curves,the ultimate shear capacity and slip were obtained.Two kinds of damage can be distinguished,namely the stud shear failure and the concrete crushing with the shear of the stud.Compared with specimens under ambient temperature,the ultimate shear capacity and the initial shear stiffness of specimens under cryogenic temperatures are higher,while the ultimate slip is lower.With the increase of the stud diameter or the compressive strength of concrete,the ultimate bearing capacity,the ultimate slip and the initial shear stiffness increase under polar temperatures.With the increase of length to diameter ratio,the initial stiffness increases.However,the ultimate bearing capacity and ultimate slip behave differently when the length to diameter ratio is more or less than 4.By analyzing of test results,an experimental equation was proposed to calculate the stud shear bearing capacity under the polar temperature.According to the model analysis of launch test specimens under different parameters,it could be concluded that the finite element analysis results can fit the tests results well.