Incremental viscoelastic analysis of composite beams with partial interaction

This paper is concerned with the time-dependent analysis of steel-concrete composite beams under service conditions. The new proposed beam model accounts for the slip at the deck-girder interface and for the time-dependent behavior of the concrete according to the incremental formulation of the linear viscoelasticity. Over each time interval, the increment of the mechanical response of the structural member is governed by a linear second-order differential equation analogous to the one of the elastic case, with a theoretical solution. The proposed model is finally validated by means of a numerical comparison with the general integral formulation and an experimental verification.