Numerical analysis of SIF and security service evaluation on thin-walled pipeline's semi-elliptical crack in NPS under heat-stress coupling load

摘要

Stress intensity factor (SIF) is one of the key parameters on analysing and studying fracture of the important parts such as pressure pipeline. This paper studied the surface semi-elliptical crack of thin-walled pipeline in nuclear power station (NPS). In order to analyse SIF, the model was established to simulate crack tip stress singularity created by ANSYS finite element. Under thermal-stress coupling load, the finite element model's K value was calculated and compared in the thin-walled pipeline entity with in shape ratio of crack (a/b) being 0.6, 0.7 and 0.8. Distribution of crack's K value and the crack propagation tendency were summarized. According to the results, it was declared that the cracks can not expand. Consequently, component will serve safety.