Abstract
In this paper, the fatigue failure evaluation method based on fracture mechanics in four pressure vessel standards GB/T 19624-2019 safety assessment of in-service pressure vessels containing defects (GB/T 19624), ASME BPVC Section VIII Div.3-2021 ARTICLE KD-4 FRACTURE MECHANICS EVALUATION (ASME VIII-3), BS 7910-2019 Guide to methods for assessing the acceptability of flaws in metallic structures Chapter 8 (BS7910) and API 579-2016 Fitness-for-Service Evaluation 9F.5 Material Data for Crack Growth Calculations (API 579) and the existing finite element method for calculating crack growth are compared and analyzed. The results show that the fatigue crack growth life of hydrogen storage vessel evaluated by fracture mechanics methods in different standards is quite different, and the fatigue crack growth life evaluated by different calculation processes exhibits different trends with the increase in stress intensity factor ratio. The safety factor should be added to the Paris model when using the finite element method to calculate the fatigue crack growth life, and the finite element method cannot assess whether the hydrogen storage vessel is safe according to the failure assessment diagram (FAD) in the conventional assessment of plane defects. This results in different termination conditions for fatigue crack calculation, and different calculated final crack sizes and fatigue crack growth lives from the results calculated by the standard process. By changing the safety factor of the fatigue crack growth life calculation method in GB/T 19624, the relative error between the calculated fatigue crack growth life and the experimental value is reduced.
