RC frames undergo inelastic deformations in the event of an extreme earthquake. Nonlinear modelling of the concrete sections is very much necessary for the simulation of realistic behaviour of RC frames in earthquake loading. Concentrated/lumped plasticity and distributed plasticity are the two different approaches for nonlinear modelling of RC elements available in literature. The main objective of the present study is to implement a displacement based fiber element (stiffness) for nonlinear analysis of RC Sections. The present study focused on the element formulation of both stiffness and flexibility based fiber models, direct integration and numerical integration and incorporation of popular confinement models for stress-strain relationship for concrete. The present study is extended to a probabilistic analysis using the implemented model. It is found that fiber elements are appropriate tool for incorporating nonlinearity in the RC sections
