thread teeth analysis

[AnsysNewUser]

Hi,

I need to get the stress on the teeth of a pair of threads(one part is similar to a bolt, the other like a nut) , to see if the teeth will fail under an axial load. We have the theoretical value, and want to get a FEA value in Pro/Mechanica. my questions are:

1) how can I make the assembly so that the teeth from the two parts "bite" each other as they should be. In 2D drawing any pair of teech should share one common line like
.....
. .....
. . .
. . ......
.. .....

2)Since the teeth is very small compare to the whole model(12teeth/in), any good suggestions for meshing? I try in AutoGEM, but failed due to small angle on the teeth, but AutoGEM works on the quater model.

I appreciate your help very much.

Anny

 

[RocketRonnie]

Have you tried "simplifying" to a 2D axisymmetric contact analysis?

 

[Nettuno]

Hi anny,

I have to perform a similar analysis.
I followed RocketRonnie advise and I got some interesting results in comparison to our expectation.
My only uncertainty is how much the initial gap I had to give to the 2 parts (nut and bolt)of my assembly can affect the final results?
Did you get some helpful results from your analysis?

Thanks in advance.

 

[AnsysNewUser]

Hi, Nettuno,

The project was canceled, so I didn't continue my analysis on the thread. However, if your load is a static one, the gap shouldn't affect the results.

Regards!