Stress and yield in thick wall tube
Stress and yield in thick wall tube
(OP)
Chaps,
Not my usual area of work but i've been looking at the stress in thick wall tube, when being injected with rubber at 12500psi!
As this tube has capped end's it generates longitudinal stress as well as the normal tangential and radial.
My stress values are :-
ID of tube =
(Radial) = -86.2MPa
(Tangential) = 562.4MPa
(Longitudinal) = 207MPa
At the OD of tube
(Radial) = 0MPa
(Tangential) = 476.2MPa
(Longitudinal) = 207MPa
Am fine with all the above working out, but become unstuck when trying to apply a stress criterion like "Von Mises"
Applying the Von Mises for ID = SQRT(((Sig1-Sig2)^2+(Sig2-Sig3)^2+(Sig3-Sig1)^2)/2)
I obtain a value of 562MPa !! if that looks familiar that’s because it is my tangential stress at the ID. Doesn't sound right to me, I would expect i higher value than one of the principal stress's.
Can any of you Pressure vessel people help me out or direct me.
Thanks all
WJW
Not my usual area of work but i've been looking at the stress in thick wall tube, when being injected with rubber at 12500psi!
As this tube has capped end's it generates longitudinal stress as well as the normal tangential and radial.
My stress values are :-
ID of tube =
(Radial) = -86.2MPa
(Tangential) = 562.4MPa
(Longitudinal) = 207MPa
At the OD of tube
(Radial) = 0MPa
(Tangential) = 476.2MPa
(Longitudinal) = 207MPa
Am fine with all the above working out, but become unstuck when trying to apply a stress criterion like "Von Mises"
Applying the Von Mises for ID = SQRT(((Sig1-Sig2)^2+(Sig2-Sig3)^2+(Sig3-Sig1)^2)/2)
I obtain a value of 562MPa !! if that looks familiar that’s because it is my tangential stress at the ID. Doesn't sound right to me, I would expect i higher value than one of the principal stress's.
Can any of you Pressure vessel people help me out or direct me.
Thanks all
WJW





RE: Stress and yield in thick wall tube
The calculation is:
(476.2+562.4)/2-(-86.2+0)/2=562.5 MPa
This value is what would be used in a pressure vessel calculation and would be compared with the allowable stress at temperature.
prex
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