JKR Contact model

Submitted by Gulniamat on Mon, 05/27/2019 - 17:58

i have some questions in my mind,
1. JKR model only describes the contact radius and normal force.
a^3=R^*/E^* [√(6 λπR^* f_n+(3λπR^* )^2 )+f_n ]
The expression for the force of cohesion, which is accounted in the eqn of motion of the particles, is missing? i mean in JKR equation there is Fn (normal force )term but no Fcoh ( cohesion force term) .
2. The value of the coefficient of restitution that we use in input scripts, corresponds to gamma_n or gamma_t?

Forums:

mschramm | Tue, 05/28/2019 - 14:51

The full JKR equation accounts for both the normal force and the cohesion force.

LIGGGHTS handles cohesion as an additional force, first calculating the normal force then later adding a cohesion force.

If you wish to implement the full JKR equations, you would put it into a normal force model and have nothing in a cohesion model.