Numerical approach for the description of different fracture modes for Zr/ZrO2 system — Deterministic and probabilistic aspects

In the context of the prediction of materials durability in multiphysics aggressive environments, we present a numerical model which is able to describe the phenomenon of the oxide layer fracture after the formation of the oxide for Zr/ZrO2 system. In order to evaluate the characteristic distance of the periodic crack pattern in the oxide layer and the debonding of the oxide/metal interface, we use a finite element model combining strong discontinuity approach and interface elements. The influence of all the parameters: the metal/oxide decohesion, the oxide layer thickness, Young's modulus ratio of the oxide to the metal, the oxide limit stress and the interface limit stress for sliding is evaluated in terms of the inter-crack distance. To take the initial defects in the material into account, we consider the randomly distributed limit stress in the oxide layer. A statistical analysis is performed to evaluate the inter-crack distance. Finally, the parameters of the numerical models will be identified from the results of experimental tests.