Numerical strategies in the application of the FEM to RC structures—I

Abstract This work addresses the influence of analytical instability on the objectivity of analytical results in the application of the FEM to RC structures. The main objective is to show that the principal causes of a lack of stability in analyses lie in crack handling procedures and the development of fictitious cracks resulting from FEA errors and inaccurate stress-strain calculations. To this end, the Ottosen models, (failure criterion and stress-strain relationship) for monotonie and short term loading have been employed. For simplicity full integrity between concrete and steel is assumed and the plane stress formulation only has been considered.