Abstract
In vessel component design by analysis, two failure modes are routinely investigated: Protection against plastic collapse and Protection against local failure. In elevated temperature service, creep rupture stress is the basis for elastic numerical analysis for establishing compliance with protection against the first failure mode. When compliance is not met, Elastic Perfectly Plastic (EPP) being a more accurate tool is proposed to verify the design using a factored rupture-based stress as yield (Sy = 1.25S). It seems that related work about adjusted yield stress has not been presented and validations are still needed using ASME VIII-2, part 5 combined load factor. Regarding local failure, an isochronous stress-strain curve has been used to determine the final stage strain for a total time duration, and compare to limits set by ASME III-NH. Code case 861 is also used to evaluate the minimum total inelastic strain and its conservativeness compared to the isochronous stress-strain curve approach.
