Calculating Friction Force with Wedge Action Modeling

[Simon666]

Hi, kind of stuck with how to calculate frictional forces in a particular problem: I am modeling yarn using mass spring system, zero dimensional nodes. Question is, what to do when a yarn can get stuck between a wedge?

How to calculate friction force vector, surface reaction and so? Since a node is zero dimensional, seems kind of impossible. Maybe I need to assume kind of finite dimensions and work with some kind of penalty method penalizing the distance between a node and the surfaces of the wedge? Still, I am completely stuck...

 

[Greg Bernhardt]

Thanks for the post! Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?

 

[Simon666]

I did not fully solve it, I managed to find a way around that is not physically 100% correct. Around my point mass, I started to look for wedge surfaces and if sum of the distances between mass point and the two wedge surfaces fell between some threshold, started generating penalizing compressive force, located along the normal on the symmetry plane between the wedge planes, and along a direction trying to put the mass point on the symmetry plane.

Friction force size is then mu times the total force vector on my mass point with the dot product of the normal on the symmetry plane of the wedge. Friction force direction is the projection of the total force vector on my mass point on the symmetry plane of the wedge, normalized and inverted.

It's not really correct but it's a mass spring model, I think it's the best I can do unless someone has a better idea.