ANSYS Bonded contact problem

[amarillogears]

Hi all,

Sorry if this is a stupid question but just can't seem to get it to work..

I have created a a geometry, frozen it and then used a Boolean operation and sliced the object to create two separate bodies, which I have then joined to create a single part. The point of this is to be able to have one body with a coarse mesh, and the other with a fine mesh. Incidentally the object is a gear.

Now when I bring it into an analysis, no contact automatically comes up between the inner and outer sections of the gear. So I manually create a bonded contact. However when I attempt to click the contact as the outer edge of the inner section, it comes up as multiple. This then results in errors when I attempt to solve. I don't know how to bond these two sections of gear back together which share a common edge? If I try to solve with no contact between them I also get nothing but errors.

Thanks!
Mitch

 

[CarlesFEA]

Mitch,

When you say "I have then joined to create a single part" do you mean that in DesignModeler you have defined a multibody part?
If so, (and asuming that now relative displacement has been done afterwards between those two parts), you should see that you have coincident nodes at the interface between parts so no contact needed.
If you are getting errors it may be due to other reasons (non contact between gears...)

Hope that helps!

Carles

 

[amarillogears]

Hi Carles, thanks for the reply.

Yes in DesignModeller I have selected both bodies (incidentally its a 2D problem), and right clicked and selected "form new part".

The thing is, I've done this before and it has automatically created bonded contacts between the inner and outer sections. However, I've had to change the location of the gears in DesignModeller, which has caused the settinds in the Structural Analysis to be cleared, and this time it has not automatically created the contacts. I've even selected the automatically create contact option, but still won't do it.

I had difficulty doing this in the last analysis as well, but for some reason or another, it just created the contact and it worked. Without the contact however I received errors.

If it would help I can send the file?

 

[CarlesFEA]

Mitch,
If both bodies are already in touch and you have created a multibody part I don't understant why you had to define a bonded contact in your initial model. Are you sure that no gap exists between inner and outer section due to the boolean operation?