EDEM2024 Bonding V2

LinYu

Dear Professor,

I would like to ask two questions regarding the bonding V2 model.

(1) Suppose a bond is generated between particles A and B. During the simulation, the bond breaks due to external loading, and the center-to-center distance between A and B exceeds the contact radius. In this case, will the bond be unable to display its fracture state as ‘2’? If so, is there any way to display the bond in this state? This is intended to characterize cracks within the material.

(2) Regarding the representation of material toughness or brittleness, how should the bond parameters be set? For example, for a brittle material, should the normal stiffness be greater than the tangential stiffness, and the normal strength greater than the tangential strength?

Thank you for your guidance.

Stephen Cole

Hi,

Thats correct, if the contact radii no longer overlap you won't be able to see the '2' fracture status. Also if the bond hasn't exceeded the force limits at that point it will break, or more accurately it will no longer exist.

Unfortunately there isn't any real way to show the bond status here, the bonds are contacts and can only show the data if they are in contact. You could write a custom model to allow for the 'preserve contact' feature to be used. Preserve contact allows contacts to exist even though the contact radii no longer overlap.

Typically the normal stiffness is greater than the tangential stiffness. You could set them to the same ratio as the materials Poissons' ratio, but I've also seen it set at a 10:1 ratio also., this does depend on the material and same for the strength. You can calibrate the values using a unconfined compression test.

Regards

Stephen