I am writing this letter for how to calculate the contact area.
In our MD studies, we use flat diamond sample and spherical tip made of diamond-like carbon which is rigid and fractal rough.
I plant to calculate the contact area use the “compute group/group” command, but only pair wise interactions are included in this calculation and 3-body potentials, such as airebo potential, cannot be used.
Then, some colleagues proposed the method of setting cutoff radius. For example, the radius of the indenter is r0 and the cutoff radius is r(r is greater than r0).Thus, the atoms of the sample which is in the cutoff radius is defined as “contact atoms”. However, I am not sure that the method of setting cutoff radius is suitable for the indenter with fractal roughness. I am afraid of the ineffective of characterizing the fractal roughness.
Would you be so kind to tell me your advice about it? I wonder if you could help me compile additional fix style which could calculate the contact area about my model and link to the Lammps.Thanks!