jakeward123

Hi guys.

I am half way through my 2nd year of a Mechanical engineering degree, we have just started compound cylinders, I am tryin to get my head around it by doing examples, but I cannot find a similar example to what I need. I have just got an assignment with one calculation, which Ive have attempted, see attatched picture for my working however I think I may have gone wrong somewhere as i came out with a negative maximum stress. If someone could point out where the mistake is that would be great. The question states:

A tube 40mm inside and 60mm outside dia is to be reinforced by shrinking on a tube of 80mm outside diameter. The compound tube is subjected to an internal pressure of 50MPa and the shrinkage allowance is such that the final maximum stress in each tube is the same. Determine the maximum stress and the difference in tube diameter before shrinkage. E=207000 N/mm^2

Thanks for your time

Jake

jakeward123

I have just worked the calculation again and got A=16666687.5 and B=26666.7 and subbing into lames eqautuon for hoop stress in and out

??in= 83.3MPa

??out= 33.3MPa

this seems a more realistic answer, showing max stress is in the inside of the cylinder. ???