Cracking analysis of RC members using polynomial strain distribution function

In this paper, an analytical model which can simulate the post-cracking behavior and tension stiffening effect in a reinforced concrete (RC) tension member is proposed. Unlike the classical approaches using the bond stress–slip relationship or the assumed bond stress distribution, the tension stiffening effect at the post-cracking stage is quantified on the basis of polynomial strain distribution functions of steel and concrete, and its contribution is implemented into the reinforcing steel. The loads carried by concrete and by reinforcing steel along the member axis can be directly evaluated on the basis of the introduced model. The prediction of cracking loads and elongations of reinforcing steel using the introduced model shows good agreement with results from previous analytical studies and experimental data. Through extension of the introduced tension stiffening model defined for tension member, a descending branch in the tension region of the concrete stress–strain relation is constructed to simulate the tension stiffening effect in RC members subjected to bending moments. Finally, correlation studies between analytical results and experimental values from idealized RC slab tests are conducted to verify the validity of the proposed model.