Residual Stresses
Residual Stresses
(OP)
Here's one I can't wrap my head around...
I have two tubes of differing material, that are concentric to each other and bonded. At 2000F they are both solid and intimately bonded throughout. I now cool them to room temp...
The outer material has a COTE of 1 and then inner material is 2 (relative to each other). They are the same thickness.
What will the stress patter in the outer material look like? Radial stresses and circumfrential?
I have two tubes of differing material, that are concentric to each other and bonded. At 2000F they are both solid and intimately bonded throughout. I now cool them to room temp...
The outer material has a COTE of 1 and then inner material is 2 (relative to each other). They are the same thickness.
What will the stress patter in the outer material look like? Radial stresses and circumfrential?





RE: Residual Stresses
For tubes with 'big'*** radius cf. thickness, I think (will need to check) (CTE_inner - CTE_outer) x delta_T x modulus = circumferential_stress (tension inner, compression outer). It's the difference in CTE's that matters, not the ratio. Also this ignores small stuff to do with stiffness and thickness of any bond material present.
Any help?
-R.
* 'long' approx. >= 4 x combined thickness of tubes.
** 'short' approx. <= 1/4 of combined thickness.
*** 'big' means radius approx. >= 5 x combined thickness.
RE: Residual Stresses
Now let me compicate it. Add a third tube on the outside of the (previously) outer material. This tube has COTE 2. So the sandwich goes 2-1-2.
Same process, and the third tube (far outside) is removed at the end.
Can you walk me through that?
RE: Residual Stresses
So the set up would be reversed.
RE: Residual Stresses
RPstress-
No shear? Aren't the tubes changing in relative length as well as diameter?
Regards.