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Press-fit contact analysis with no load--unable to run

Forum|Forum|8 years ago
September 25, 2017
5 replies
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I have a simple contact analysis that I would like to run. I have a gear that is press-fit onto a shaft. Instead of enforcing a displacement (the distance the gear in pressed onto the shaft), I wanted to start with the gear already in it's final location and simply run the analysis with the press-fit box checked and the maximum interpenetration set to my press-fit distance (0.038mm in this case). However Simulate gives me an error that I can't define the analysis without either a load set or enforced displacement. Is there a setting I have incorrect? I thought I could run a press-fit without needing a load set or enforced displacement. I've attached my assembly with the setup I'm having issues with.

1_Contact_Analysis.zip

General

Best answer by 346gnu

Stephen,

I ran it as was upoaded using one of the predefined studies in the zip, it immediately failed (as expected) as there where no loads.

I made the following single change:

ADD a global temperature load at assy level with zero ref temp and zero model temp. This gives me the zero load - or as I refer to it, a 'dummy' loadset to make the s/w carry out the static study.

Running the model : The model failed insufficiently constrained (as expected) the female part rotates/translates on the frictionless contact. The residual norms in the .pas file show that something is moving somewhere.

insufficiently constrained.jpg

So I added 2 light springs to prevent spinning/axial transltion of the female component on the shaft. I changed nothing else at all and it ran no problem in about 2 minutes.

with light springs.jpg

contact pressure.jpg

NOTE I am viewing MPa

It took me far longer to write this than to fix and run

I don't understand why you are getting internal engine errors. What version of the s/w are you using?

This was Creo3.0 M120

Charles

3

346gnu

13-Aquamarine

As well as a zero load Stephen mentions, (which simply fools the software into thinking there is a load set so that it runs a static analysis),

you will need a light spring or two to prevent the female part translating axially or rotating ... contacts are by default frictionless and the model will likely fail insufficiently constrained. If it doesn't fail it may take a much longer time to solve.

Deselect the Press fit (initial interpenetration) check box, this is irrelevant in your case and just confuses.

bfn

G

gpommeranz

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