Simplified J estimation methods for cracked cylinders under combined thermal and mechanical loading

In the field of non-linear fracture mechanics, a lot of work has been done on structures submitted to mechanical loadings. However, for thermal loadings and particularly for thermal shocks, only few results are available. The aim of this paper is to present the main results of a complete set of finite element (FE) computations, conducted by CEA, EDF and FRAMATOME, on cracked cylinders submitted to combined mechanical and thermal loads. The interaction between these two types of loads is analysed in the cases of austenitic and ferritic structures. Moreover, these results are compared to the predictions obtained by simplified engineering methods (R6 procedure and two French approaches) in order to improve them. Their domain of validity is also discussed.