Using VIII-2 Part 5 on a VIII-1 design: what about protection against cyclic loading

[keyen]

When using Section VIII-2 Part 5 elastic-plastic analysis (with a load factor of b=3.5 for protection against plastic collapse; and 1.7 for protection against local failure) on a vessel (or component of a vessel) that is designed per VIII-1 (and U-2(g)), is it a generally accepted engineering practices to apply Part 5 in full (including Paragraph 5.5: protection against failure from cyclic loading). Or is the load factor against plastic collapse (b=3.5) high enough to eliminate the risk of cyclic failure modes?

 

[keyen]

TGS4, I assume your post on this topic is still valid: [URL unfurl="true"]https://becht.com/blog/performing-an-fea-in-section-viii-division-1-to-qualify-an-article-u-2-g-component[/url] and you recommend meeting all the requirements of Part 5.

 

[TGS4]

I certainly recommend taking in all of Part 5. You can perform a screening assessment to determine whether or not you need to do a full-blown fatigue analysis. However, a ratcheting assessment is always required.