principal stress for ellipsoidal head

[farzam]

Dear All,

Per ASME VIII-div2, principal stresses for cylindrical and spherical shell are specified(4-221,4-321). please let me know if I may use the formulas mentioned for spherical shell (4-321)to specify the principal stresses of ellipsoidal head.

Thanks in advance

 

[prex]

Well, no, not really.
You can find the general equations for the principal stresses in any shell of revolution in the Roark; these do not consider the variation of stress across the thickness, so are only valid for thin shells.
If I'm not in error, these would give
[σ]₁=PR/2t
[σ]₂=-PR/t
at the junction with the cylinder (apart of course from the discontinuity stresses) for a 2:1 ellipsoid.

prex

http://www.xcalcs.com

: Online engineering calculations

http://www.megamag.it

: Magnetic brakes and launchers for fun rides

http://www.levitans.com

: Air bearing pads