I need a formula to calculate the plastic buckling pressure for a torispherical and an ellipsoidal heads.
What is ECCS formula for this plastic buckling pressure ?
ECCS is European Convention for Constructional Steelwork and published the following document:
- "Buckling of Steel Shells, European Recommendations", 1988.
I need calcute the stress during hidro test for an ASME vessel. The formulas of ASME code (Addenda 2003), for torisherical heads, overestimate stress in this condition.
Harvey's "Pressure Component Construction" Ch. 2.6.4 has a section on this. Basically, if axis ratio a/b > 1.42, this can be a problem.
It makes quite a memorable sound when it goes, too [as in "what the #$%%#@ was that?"].
We had one once on a "non-code" [as in "it doesn't have to be engineered, it's less than 15psi"] tank with shallow, thin ends ("to save $$". The shop boys were leak testing the pipes, with city pressure in/ a partly open ball valve on the outlet for back pressure. A loud Boinnngggg resounded throughout the shop. The tank knuckle-buckle looked just like the picture in Harvey. Funny how the immutable laws of physics hold true, even when managers hold a meeting & decide they don't apply. "Get out the fender tools, boys!!" ;-)