Intégration numérique de lois de comportement élastoviscoplastique endommageable et applications

ABSTRACT Numerical simulation of creep rupture of a reactor pressure vessel in a severe hypothetical accident needs to perfectly take account of interactions between creep phenomena and damage. This paper presents a numerical method for solving constitutive equations of a material behaviour model coupling elastoviscoplasticity and creep damage through the effective stress concept. The numerical technique rests upon a semi-implicit time integration of the constitutive equations. The method is validated on both simple ID cases the results of which can be compared to other numerical or analytical solutions and in the case of an axisymmetric reference problem (RUPTHER 4 test) under thermal and mechanical loading. The efficiency of different tangent stiffness matrices is analysed.