Nonlinear analysis of reinforced concrete beams submitted to bending moment gradients considering the variable adhesion model

The objective of this work is to evaluate the nonlinear behaviour of beam elements of structural concrete, subjected to asymmetric bending, delimited by two consecutive sections of discontinuity (cracks or open joints), considering the variable adhesion model. For this, two algorithms were developed using the MATLAB tool from the numerical solutions presented herein. The first refers to the equilibrium of sections subjected to asymmetric bending. The second calculates the equilibrium of sections considering the bond-slip effect, maintaining the Bernoulli-Navier hypothesis where perfect adhesion is no longer possible. Two numerical applications (simply supported beams) are used to validate and verify the efficiency of the developed models and algorithms. Results obtained shown that there is a good agreement with the experimental results found in the literature, characterising a good alternative for the evaluation of the nonlinear behaviour of beam elements, when there is a loss of adhesion.