[EDEM] what is usNormalForce in EDEM contact model API?

KJHSNU

Hello,

I have a question regarding the usNormalForce parameter of the calculateForce function in the EDEM contact model API.

I looked at the documentation, and it describes usNormalForce as follows:"/**< The unsymmetrical normal forces on element 1. This represent the portion of the calculated normal force that causes energy loss / gain (eg damping). */"

Does this "unsymmetrical" part mean that by using usNormalForce, unlike normalForce, I can apply a force asymmetrically, i.e., only to element 1?

For example, if I write usNormalForce += F; inside the calculateForce function, does this mean that element 1 receives the force F, but element 2 does not receive the force -F?

Thank you.

Stephen Cole

Hi,

usNormalForce is the damping component of the force. For a contact model it's always equal and opposite for a contact pair, just the force is split into the damped and undamped component. The "unsymmetrical" part of the name is a bit misleading in that respect.

IT's worth noting the force reported in the Analyst is the undamped force. There is some further discussion here:

https://community.altair.com/discussion/comment/28883#Comment_28883

Regards

Stephen