Modelação numérica do escorregamento de armaduras em elementos de betão armado / Numerical modelling of bond-slip effects in reinforced concrete elements

Reinforced concrete (RC) framed structures subjected to seismic loading often show localized deformations at the extremities of the members associated with the slippage of reinforcing bars along their anchorage length. Despite this phenomenon being responsible for up to 40% of the total lateral deformation of RC members, the numerical simulation of this behaviour still presents several limitations. This paper introduces a modelling strategy wherein, for the first time, an explicit bond-slip model is developed to be used in connection with a fibre-based beam-column element through a zero-length link element. The proposed element adopts an advanced bond stress-slip constitutive relation capable of representing the effects of cyclic degradation or rebar yielding, among others. The numerical model is validated through a comparison with experimental results, evidencing a remarkable efficiency, accuracy and numerical stability.