Creep Deformation Analysis of a Pipe Specimen Based on Creep Damage Evaluation Method

After the Fukushima Daiichi nuclear power station (1F) accident, it has become more important to develop methods for evaluating the failure behavior of the nuclear components under severe conditions. We are, therefore, researching prediction methods for creep deformation and failure behavior of nuclear components under elevated temperature conditions based on finite element analysis. In this study, as part of a project called Components and Structures under Severe Accident Loading (COSSAL), we perform failure analysis of a large-scale pipe experiment to validate our prediction methods based on a creep damage evaluation method. The analytical results obtained from the conventional Norton and modified Garofalo constitutive laws, as well as the Kachanov-Rabotnov law considering material damage due to creep deformation, were compared with experimental results. We conclude that the Kachanov-Rabotnov law allows for the most accurate analysis among the three creep constitutive laws considered herein.