A non-linear finite element model is presented for the analysis of simply supported reinforced concrete beams. Cracked concrete is considered as an orthotropic material and the crack formation is simulated as smeared cracks. A rotating crack method is employed based on the total strain crack model. The analysis was carried out with the help of 2D isoparametric plane stress elements. Compression and tension softening and tension stiffening effects of the cracked concrete were considered. The tension reinforcement consisted of either steel or fiber reinforced polymer (FRP) bars. Excellent convergence and numerical stability of the formulation was found. The model showed good agreement with the recorded data of the tested beams.
Rafi, M. M., Nadjai, A., & Ali, F. (2007). Analytical modeling of concrete beams reinforced with carbon FRP bars. Journal of Composite Materials, 41(22), 2675-2690. https://doi.org/10.1177/0021998307078728