Nonlinear Analysis of Reinforced Concrete Beams using FEM with Smeared Crack Approach, Mohr’s Failure Criteria, and The Tomaszewicz Model

Abstract

Cracking has a predominant effect on the failure mode of reinforced concrete beams. Their presence results a nonlinear stiffness behavior. Previous research work explained the concrete cracking process due to the exceeding of the major tensile principal stress to the concrete tensile strength only. The effect of the minor principal stress is neglected. This incorrectness results a less precise prediction of crack propagation and beam failure. Hence, an advanced analysis predicting the occurrence of cracks and taking into account the presence of biaxial principal stresses, is developed. The nonlinear finite element analysis is used to calculate stress and strain. To model steel reinforcement and the concrete cracking, the smeared element and smeared crack approach are chosen. The material behavior is consider nonlinear, while the bond slip effect and dowel action is neglected. The existence of cracks as a result of the combination of normal and shear stress is predicted based on the Mohr’s failure criteria. The uniaxial concrete stiffness-modulus, not constant under incremental loading, is generated by the Tomaszewicz model. The load–displacement curves of analyzed beams are validated with identical laboratory tested specimens.