Parts on top of fasteners

[rbrooks]

Can anyone tell me how to solve a problem I have with assemblies I am trying to model.

I have a frame work which is fastened together with fasteners and this works prefectly well until I add extra parts.

In reality the frames are connected using countersunk fasteners some of which are then covered with panels. When I add the side panels which cover the fasteners I am told by Autogem that "The fastener references are not oriented correctly" and I cna't find a way to fix this.

This thread is inactive and closed by the PTC Community Management Team. If you would like to provide a reply and re-open this thread, please notify the moderator and reference the thread. You may also use "Start a topic" button to ask a new question. Please be sure to include what version of the PTC product you are using so another community member knowledgeable about your version may be able to assist.

[TomD.inPDX]

Creo allows for rotational freedom in constraining parts.

I wonder if this is causing an issue with the next level association.

[StephenBerkeley]

Hi Richard,

Could you please file a case with Technical Support ? Thanks ...

[rbrooks]

No I can't. Several problems:

1. I can't work out how to properly describe the problem in only 225 characters.

2. I can't find out what the datecode of the software is (which is required)

3. I don't know what the SCN number is (This is required, I know we have one but without this I can't do anything)

[Alain]

What happens when you add an orientation as third constraint for the fasteners? Is the problem solved then?

[SylvainA.]

Did you try to add contact interfaces between the frame and panels to see if it can help ?

Do you see anything strange with the "Review Geometry" tool ?

[rbrooks]

Yes there is a contact constraint between the frame and panels & nothing strange shows up with review geometry.

[danderson · Accepted solution]

I have run into a similar issue where another part touches the head of a Mechanica fastener and fails.

As far as I know if you need a part to touch a fastener you will need to fully model the fastener (physical part) and add proper constraints.

You might try adding a relief cut to add clearance around the head of the fastener to the touching part.

I know this is not ideal but might help you trouble shoot your issue.

Someone else might be able to correct me on this?
Can we add contact constraints between Mechanica fasteners and other parts?

Hope this Helps,

Don Anderson

[346gnu]

Perhaps is something to do with the annular surface region that is created to connect the fastener element via weighted links? Adding your extra parts over the top covers this over and may upset this region/link somehow.

Should be easy to test on a simple 1 fastener model.

... Pro/E version available via HELP > ABOUT

[rbrooks]

Thanks Don.

Adding a relief cut works OK, unfortunately it add complexity to the mesh.

It also appears that the problem doesn't occur if screws are used instead of bolts and the thread end of the screw goes onto the covered hole surface with the head end on the surface which isn't covered.

This isn't perfect either as bolts and screws act differently but both methods are adequeate for a lot of applications.