Volume Spring Model (Polyhedral)

The Volume Spring model is an experimental model in which the normal force is proportional to the overlap volume of the 2 particles and does not involve the penetration depth. This is similar to Govender and Chen models which also use force proportional to overlap volume. In some cases this has been found to give enhanced stability of contacts. The form used in the EDEM implementation for the normal spring force is:  

 

 

 

The damping force is calculated using the differential stiffness of the normal spring force. This is based on an analogy with a linear spring model, and the coefficient in this relationship is adjusted to give the correct coefficient of restitution for edge to face contacts. The tangential force is calculated using a tangential stiffness which has the same ratio to the differential normal stiffness as the Hertz-Mindlin model. 

 

The Volume Spring Model is made available in the Options Menu>Additional Components>Experimental Contact Models.  Once enabled Volume Spring will appear in the Contact Model Chain (experimental contact models are highlighted in green).