Non-Linear Sectional Analysis of Reinforced Concrete Members

Abstract

In the most general case 3D reinforced concrete frame are subjected to complex load states that lead to a combination of axial and shear forces, torsion and bending moments on each frame element. Material non-linearity produce an anisotropic behavior that leads to the coupling between all the six efforts. In this work a sectional model and code for non-linear analysis of reinforced concrete member developed by other authors is presented. This model is able to reproduce the complex coupled behavior of a reinforced concrete section and can be used as a constitutive equation on each integration point of any flexibility based frame model. In order to contribute to the improvement of the sectional model and the implemented code, a plastic-damage model based in plasticity theory and fracture-energy damage concept is presented and implemented to model concrete behavior. Also a unified library of non-linear solver schemes is presented and implemented to allow the code to deal with highly non-linear problems. Finally the code with the new constitutive law and non-linear library is tested trough a series of examples showing the capabilities of the sectional analysis.