Fatigue performance and stiffness variation of stud connectors in steel–concrete–steel sandwich systems

In this study, a series of fatigue tests on six nominally identical push-shear specimens is conducted. The test specimens were subjected to an initial quasi-static test, up to a predefined maximum load, followed by a fatigue test to failure. For all the fatigue tests the mean applied load was the same while the load range varied to induce fatigue failure. The push-shear fatigue tests indicated that stiffness of the shear connections is gradually decreased during the test. Overall, the test results revealed that the lifetime of steel–concrete–steel sandwich systems under cycling loads could be predicted beforehand through the evaluation of the stiffness reduction in shear connections.

► A series of fatigue tests on six identical push-shear specimens is presented.
► The specimens are considered as steel–concrete–steel sandwich systems.
► Fatigue performance and stiffness variation of stud connectors are investigated.
► The stiffness of the shear connections is gradually decreased during the test.
► Evaluation of the stiffness reduction enables lifetime prediction of such systems.