Efficient technique for constitutive analysis of reinforced concrete flexural members

One of the most difficult issues in the theory of reinforced concrete (RC) is an adequate modelling of deformation behaviour, cracking and, particularly, post-cracking behaviour, as one of the major sources of non-linearity. Applying the concept of average cracking and average strains, deformation behaviour of RC can be modelled by stress–strain tension–stiffening relationships. The authors proposed an innovative inverse technique for constitutive modelling of flexural RC elements. The technique is based on the smeared crack approach and layer model of RC section. The inverse technique aims at deriving tension–stiffening constitutive models from experimental moment–curvature diagrams. The present analysis takes into account the shrinkage effect that is often neglected in other studies. Based on the inverse technique, free-of-shrinkage tension–stiffening relationships are derived using test data of shrunk RC beams. Examples of the application for the analysis of the experimental data obtained by the authors are presented to illustrate the calculation efficiency of the proposed technique.