[lammps-users] Triaxial Test for granular particles

Dear LAMMPS users,
I want to perform the triaxial test simulation for granular particle confined between wall. I am not sure how to go ahead or whether LAMMPS has this capability to perform these simulations?

Any kind of suggestion would be most welcome in this regard.


What is a triaxial test?


Hi Steve,
These is something like uniaxial compression test (not exactly similar) but in triaxial compression test, the compression takes place in almost isotropic condition. The top and bottom boundaries moves vertically as loading platens, either under force-controlled condition or under strain controlled condition. On the lateral walls a confining pressure acts.

You can read this wiki page for more information,



If the walls are frozen particles, then you can move them however
you wish. See the fix move command. If they are flat, ideal walls,
then you can move them via fix wall/gran. Or just use fix deform
to change the shape/size of a periodic box.