Creep-Damage Analysis: Comparison Between Coupled and Uncoupled Models

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. The continuous damage theory enables to formulate models strongly coupling elasto-visco-plasticity and damage. Such models have been implemented in various computer codes and, in particular, in ASTER at Electricite de France, CASTEM 2000 at Commissariat a l'Energie Atomique and SYSTUS+® at SYSTUS International. The objective of this paper is to present briefly a validation study of the three different numerical implementations and to compare the coupled approach to an uncoupled one on an example of a cylinder of the program RUPTHER, under internal pressure and heated to a temperature of 700°C.