NUMERICAL STRATEGIES IN THE APPLICATION OF THE FEM TO RC STRUCTURES .1.

This work addresses the influence of analytical instability on the obj ectivity of analytical results in the application of the FEM to RC str uctures. 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 inaccu rate stress-strain calculations. To this end, the Ottosen models, (fai lure criterion and stress-strain relationship) for monotonic and short term loading have been employed. For simplicity full integrity betwee n concrete and steel is assumed and the plane stress formulation only has been considered.