Elastic Follow-up Factors to Estimate C(t) for Circumferential Internal Axisymmetric Cracked Pipe under Secondary Stress

This paper proposes a method to determine the elastic follow-up factors for C(t) -integral under secondary stress. To estimate values of C(t) for secondary stress based on the reference stress method, elastic follow-up factors of cracked structure are needed. The present paper proposes a method to estimate elastic follow-up factors of cracked structure under pure secondary loading. The elastic follow-up factors for plasticity and creep are identical due to Hoff‘s plastic-creep analogy. Thus elastic follow-up factors for C(t) can be determined by elastic-plastic finite element (FE) analyses. To verify this method, FE analyses for circumferential internal axisymmetric cracked pipe under thermal loading was performed. The Proposed approach gives good agreement with FE result.