It seems that although I can specify friction in a 3D contact, I cannot measure the friction force because 3d contact is not a mate. The results property manager demands a mate.
Is this how it is?
See if the attached movie explains more clearly the workflow.
Your model has a coincident mate, presumably between box and ramp, yet the box separates from the ramp plane. How can this be?
In this situation I use a mate for positioning the box on the ramp, then suppress it because in real life boxes are not constrained to ramps, and wheels are not constrained to the road; they can climb the curb given sufficient lateral force and friction. I want to measure the friction force on the curb.
My positioning mates are already suppressed when I open the Results PM. LC on a face pops up the same help message that shows in my graphic. The face is not accepted by the PM.
I actually had 2 coincident mates,1 between the box and the inclined plane for initial positioning and a second to keep the box in plane (ie a 2-D problem).
So the 3D contact is driving the resulting motion and the frictional forces.
The main requirement is to plot the frictional forces between the contacting faces of interest. There is the option to use a reference component for the friction directions, but I need to investigate further what's really going on here as in the example of mine, I was getting friction components normal to the plane (I used the box as my reference frame), so I have to double check it was really using the box reference frame.
My recollection is that the Reference frame is not the local frame that users want, but a copy of the global frame.
My immediate problem is that I don't have any mates between the contacting faces, and the Results PM will not accept selections of faces to identify where the friction is.
Can you show an image of the geometry you are trying to plot the friction on?
The reference frame uses the coordinate system of whatever part you select, so for example, the box has it's x-axis down the slope, so i would expect plotting just he x-component of friction using the box as my reference compoent would give me the full amount of friction along with the relative direction 9as magnitude just gives the amount).
I can't recall what version of Sw you were using but I can post the sample model I did to see if you can reproduce the workflow on that one. I did it in 2010sp4
The Reference frame is not the issue unless it is a necessary, rather than optional, parameter.
The Mate is the issue.
Will your model work with all mates suppressed?
Yes, it does work without both mates.
I've attached it.
Another option you have to plotting the friction is to plot the contact force result component normal to the surface. This needs the reference frame in most cases to work. I did it in the attached model and it gives the same result.
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