# [lammps-users] finite wall with friction

Hi

I would like to create a finite wall (with z as normal and bound on x and y) with friction? Is there a way to do it using fix wall/gran or anything else?

Thanks,

Somnath

Fix wall/gran will exert tangential friction on granular particles.

Steve

Thanks Steve. I need to exert a tangential friction on granular particles.

But how do i create a finite wall using fix wall/gran? It seems to me that only an infinite plane may be created.

What do you mean by a finite wall?

Steve

Steve,

When i define a wall with fix wall/gran, for ex.

fix 10 all wall/gran 2e10 7e10 50.0 50.0 0.5 1.0 zplane 9.0 NULL

it creates a wall at z=9.0, with normal as z-axis and extending infinitely in x and y directions (or the xy plane at z=9.0)

Instead, I want a wall as above but extending only between, (say) x=0 and 5.0 and y=0 and 4.0
This is what i mean by a finite wall. Do you get me now?

Thanks
Som

You'd have to write/modify such a fix yourself. And worry about
what it means for particles to see the edge/corner of such a wall.

Steve