James,

Beam Element models (Such as Caesar II) are wonderful tools. However none the less pressure and pressure cycling will not have a large impact on properly supported beam element models results!

However, the previous statement not withsatnding pressure cycling may indeed cause COMPONENT fatiuge failures!

However note the key word (COMPONENT). The simplified rules of ASME b31.1 or B31.3 provide no specific directin on component (three dimensional) analysis or should I say "design by analysis (Ref ASME Sect VIII Div2)". The closest code that incorporates some of the concept of pressure within a beam element model is Section III NC.

So if you have a pressure cyclic problem where pressure is a large component of the loads look at more advanced methods of analysis.



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Best Regards,

John C. Luf