Behavior of shear studs subjected to fully reversed cyclic loading

A series of experimental and analytical tests on modified composite push-out specimens and bare steel shear studs were performed to investigate the behavior of shear studs subjected to fully reversed cyclic load. Of specific interest was the behavior under low-cycle fatigue. Such load would be applicable to composite or hybrid structures subjected to seismic events. An overview of previous research in the area of shear stud behavior is included. Reversed cyclic loading resulted in an almost 40% reduction in shear stud capacity compared to static capacities. This reduction occurs due to low-cycle fatigue of the stud/weld materials as well as concrete degradation. Existing relationships for concrete strength predicted the change in capacity under static and low-cycle fatigue loads. Initial bending of studs did not affect the shear stud load capacity. While shielded metal arc welding of shear studs provides a very different stud base condition, the percentage reduction in capacity was similar. Boundary conditions in push-out specimens did not significantly affect the initial bending and shear stresses, which appear to control failure modes.