Session: CS-07-05 The Warren H. Bamford Memorial Symposium on Recent Developments in ASME Codes and Standards-5

Paper Number: 151489

151489 - 2025 Update to Asme Section Viii, Division 2, Part 5 - Design by Analysis 

Abstract: 

The 2025 Edition of ASME Section VIII, Division 2 will contain the most substantial revision since the entire Section VIII, Division 2 was rewritten in the 2007 Edition.  Below are the highlights of the changes made.

A new Section is inserted into paragraph 5.6, titled, "Protection Against Creep Damage".  This new section details new damage modes that require demonstrating protection against.  The first subsection is "Protection Against Stress Rupture From Load-Controlled Loads".  Design-By-Rule methods are referenced, as is an elastic stress analysis method.  The second subsection is "Protection Against Stress Rupture From Load-Controlled Loads Plus Occasional Loads".  Again, Design-By-Rules methods are referenced, as is an elastic stress analysis method.  The third subsection is "Protection Against Creep Buckling".  In this subsection, the analyst is referred to Method B in paragraph 5.4, with modification appropriate for creep - namely usign an isochronous stress-strain curve instead of the elastic-plastic curve.  The fourth subsection is "Protection Against Failure from Creep Fatigue".  Here, creep-fatigue screening methods are introduced.  A specific creep-fatigue analysis methodology is not yet introduced, although the framework for one is laid out in the form of the paragraph.  The fifth and final subsection is "Protection Against Creep Ratcheting".  In this subsection, an elastic analysis methodology and an elastic-Visco-Plastic analysis methodology are presented.  Note that these subsections generally follow the flow of the prior paragraphs in Part 5.

The fatgiue screening methods in paragraph 5.5 are also updated.  Method B had been updated in the 2023 Edition.  A new Method C is introduced, which is almost identical to Method B, except that instead of the smooth-bar fatgiue curves, the Structural Stress welded fatigue curves are used.

The fatigue analysis methods themselevs are also updated, in order to bring them into alignment with ASME FFS-1/API 579-1 (2021), as well as proposed and approved changes that are not yet published in that document.  The rahcteing assessment is also updated substantially.  Based on prior work by Seipp (2024), the elastic analysis ratcheting limits are changed.  Additionally, a new elastic analysis method, based on the Bree Diagrams, are also introduced.

In paragraph 5.2, two stress limits that were in the Code prior to the 2007 rewrite are reinstated: Bearing Stress Limits and Shear Stress Limits.  These limits are identical to the limits previously contained in the 2004 Edition.

Finally, the entirety of Part 5 received a signficant editorial revision.  The entire Part is brought into conformance with the ASME Style Guide.  Cross-references to paragraphs, equations, Figures, and Tables have been fixed.  Variables in the nomenclature have been cleaned up.  And a variety of paragraphs have been simplified using the "Clarity Rewrite" approach that other portions of the Section VIII Code are undergoing.

Presenting Author: Trevor Seipp Becht

Presenting Author Biography: Trevor Seipp is the Canadian Operations Lead for Becht. He is a world-renowned expert in the field of design-by-analysis. He is a member of numerous ASME Code Committees. He is an ASME Fellow, and a recipient of ASME's Dedicated Service Award. He was the Chair of PVP2020, and is a past-Chair of the PVP Division.

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