About fix set force

Dear lammps users,

I am trying to simulate a stretching test and one end of tube containing carbon are clipped. I want to allow motion in x y direction and set motion in z direction =0. I tried to use setforce zero only in z direction but does not allow me to do so. Can someone please suggest me way to solve this small problem.

Thank you,
Arun

How do you mean, “does not allow me to do so”? According to the documentation it should totally be possible, so you need to show us how it goes wrong before we can help you.

Dear lammps users,

I am trying to simulate a stretching test and one end of tube containing
carbon are clipped. I want to allow motion in x y direction and set motion
in z direction =0. I tried to use setforce zero only in z direction but
does not allow me to do so. Can someone please suggest me way to solve this
small problem.

​please have a look at newton's equations of motion. setting the force to
zero is a prerequisite, but not sufficient to immobilize an atom. it will
only result in no change in velocity. thus you also have to set its
velocity to zero.​

axel.