Beneficial effect of friction on the fatigue life of shear connectors

In the design of steel-concrete composite bridge beams, it is assumed that the shear connectors carry all of the longitudinal shear force developed at the steel-concrete interface. In reality, however, friction at the interface reduces the longitudinal shear force acting on the connectors. A finite element program has been developed to model the effects of friction at the steel-concrete interface of composite bridge beams subjected to either static or vehicular fatigue loading. The analyses have shown that friction reduces the longitudinal shear force relatively uniformly along the length of a simply supported beam. The implication of this is that the design life of stud shear connectors may be greater than that currently assumed.