Manson-Coffin- and Ramberg-Osgood relation for headed shear studs in fatigue loading. (LAC07.A)

Welded shear studs in composite bridges are subjected to statical as well as fatigue loading. To proof the fatigue resistance, the so-called Wöhler curves (S-N curves) have been established. The slip displacements in these bridges between concrete slab and steel girder however show that, the loading on the studs is more displacement than force controlled. Results on displacement-controlled fatigue push-out tests on shear studs are presented to describe the correlation between slip and bearable load cycles with the Manson-Coffin equation and the correlation between shear forces and slip with the Ramberg-Osgood equation. Both relations are combined to obtain an assessment of internal forces as well as displacements for the verification of the fatigue resistance.