Abstract
Thermal fatigue assessment is often required for high temperature components such as those in thermal power and chemical plants. The procedures used to evaluate fatigue life consumption of a component subjected to cyclic non-steady thermal loading are rather complicated and, in many cases, difficult to carry out. In addition, experimental validation of a thermal fatigue assessment by using FEM has been rarely carried out due to the high cost and length of time required to perform tests where a specimen is subjected to cyclic thermal loading. This study deals with a test previously performed by JAEA in their sodium flow test facility. The stress-strain history imposed on the specimen was mainly non-proportional. In this study finite element analyses, non-steady-state thermal transient and stress analyses were performed using open source FEA software (Salome-Meca, Code-Aster) to evaluate changes in thermal stress and strain. The simplified assessment methods previously proposed for determining the pair of time steps that define the maximum stress range were applied and subsequently compared.
