Force exerted by an ID mandrel 2

[josephn16]

I hope I can explain this situation well enough, because it is a bit difficult to explain without a drawing:

A co-worker of mine is doing a study of a possible interference fit for a product we make that is essentially a ceramic tube with a steel mandrel on the inside. The whole assembly goes into a furnace and is used as a drive system. At design temperature, the mandrel expands so that there is an interference fit with the tube (due to a design error). He has calculated the force exerted with one big (I think) assumption, that the force is exerted from the outside in and not from the inside out as is actually the case. I believe that this is due to a limitation built into the software he is using to calculate the force.

I want to say that the calculation is not really valid, but I do not do this type of thing often enough to be sure, any thoughts?

 

[Cockroach]

I would think you are correct, the force is due to an internal interference fit at elevated temperatures. This would be equivalent to saying that the ceramic tube is shrunk onto the steel mandrel, given some specified temperature.

You should be able to quickly calculate the force by hand. Take a look a previously posted threads in this forum, interference fits have been extensively discussed as of late.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[desertfox]

Hi josephn16

Have a look at this thread:-

thread404-42504

hope this helps

regards desertfox