Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations TugboatEng on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

ASME 8 Div-1 tmin thickness basis for thick cylinder

Status
Not open for further replies.

NovaStark

Mechanical
Joined
Feb 11, 2013
Messages
260
Location
US
Good day all,

From ASME 8 Div 1 for a cylindrical tube under internal pressure, the minimum thickness is based off the simple hoop stress equation:

S = PD/2t once the cylinder is considered thin for a particular range of t/D.

Now if the thickness exceeds that or the pressure is greater than some calculated value, the code gives a different equation:

t = R[exp(P/SE)-1]

What stress is this based on? It does not seem to fit the Lame model for thick cylinders due to the exponential function.
 
ASME PTB-1 has this equation derived in section 4.3.3. Per PTB-1, it is based on limit analysis theory using the tresca yield criterion.
 
Much thanks.

For the Div.1 formula, any idea on why 0.6P is taken away from SE ?
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top