Study on characteristics of the elastic follow-up coefficient for the 3 kinds of inelastic behaviors

Abstract

In the structural design of fast reactor equipment, structural strength is evaluated using elastic follow-up coefficient considered stress relaxation by creep. JSME standard for fast reactor limits the strain to prevent excessive inelastic deformation and the creep-fatigue damage factor to prevent failure due to fatigue and creep-fatigue. In case of the long-term primary stress is low, elastic follow-up strain, creep damage factor and strain range used to these limits is calculated according to elastic follow-up coefficient: q=3. Therefore, in order to adopt more reasonable design, JSME standard will be proposed that can use elastic follow-up coefficient: q^r calculated from the results of inelastic analysis instead of q=3. In this paper, it’s shown concretely how to calculate three kinds of elastic follow-up coefficient described above, and shown elastic follow-up coefficient calculated from repeated behavior with respect to strain range is smaller than others.