Finite-Element Modeling to Calculate the Overall Stiffness of Cracked Reinforced Concrete Beams

The macro-finite-element (MFE) modeling proposed in this paper is dedicated to the calculation of the deflection of already cracked reinforced concrete beams under service loading at the stabilized cracking stage. MFEs are beam finite elements, characterized by their average moment of inertia, calculated using nonlinear assumed distributions of steel strain, concrete strain, and neutral axis between two consecutive bending cracks. The results of the MFE model are successfully compared with experiments performed on five RC beams, including square- and T-section beams and two concretes (grades 30 and 40 MPa). A successful application of the MFE method to a statically indeterminate beam is also presented. The MFE modeling is appealing for use in practice because of its computational simplicity.