Behaviour of headed stud shear connectors under low-cycle high amplitude displacements

Two series of pull-push specimens embodying headed stud shear connectors we re built and tested as part of a general investigation on aseismic design o f steel-concrete composite beams. Thereby, both the geometrical and mechani cal characteristics of specimens are similar to those of steel-concrete com posite substructures with full and partial shear connection. Specimens were endowed with different boundary conditions in order to asses s the relevant effects on the response. Moreover, to characterise the speci mens from a seismic standpoint, they were subjected to suites of monotonic, variable and constant amplitude displacements according to a cumulative da mage test program. Main results are commented upon and assessed in terms of both yielding and maximum shear strength capacity as well as ultimate displacement ductility. Finally, a comparison between experimental and ideal loads derived by rele vant codes provides an estimate of their accuracy.