the Hertz-Mindlin with JKR contact model: A question about the negative overlap.

Yu Mu

Hello everyone,

In the EDEM 2020.2 document, the normal force-negative normal overlap is described as follows:

In the description of the document, the negative overlap is allowed, and will still produce cohesion after particle separation. But the document mentioned at the end:

Does this mean that it is impossible to calculate the case where the overlap is negative?

I also see the following figure in the case of EDEM Tutorial： Transfer Chute and JKR Model:

The above figure shows the force won't be calculated if the overlap is negative in EDEM.

I'm confused about this. Can this model calculate the force of negative overlap, as described in the document?

Stephen Cole

Hi,

 

The JKR v1 model doesn't correctly calculate the force if the overlap is -ve at the point of first contact.  The attractive force at -ve overlap should really only happen after the physical contact has happened.  In the v1 model this force will happen as soon as the contact radii overlap, in the v2 JKR model this attractive force will only occur after the physical contact has occurred and the particles are pulling apart.

Regards

Stephen