Modèle de plasticité et d'endommagement pour le comportement du béton
Résumé
Elastic damage models or elastic plastic constitutive laws are not totally satisfactory to describe the behaviour of concrete. They indeed fail to reproduce the unloading slopes during cyclic loading which define experimentally the value of the damage in the material. When coupled effects are considered, the capability of the numerical model to reproduce the unloading behaviour is essential, as an accurate value of the damage is needed. An elastic plastic damage formulation is so proposed to circumvent the disadvantages of both approaches. It is first tested on uniaxial tensile loading. It is then applied on one cyclic compression to highlight the improvements of the presented law (volumetric behaviour). Finally, a « passive » confinement test is proposed to underline the importance of using a plastic—damage approach for the simulation of a composite structure (steel tube with concrete).