a question about tensile deformation with the boundary s s p

I have also examined these commands, but they were not useful.

To apply tensile deformation to a periodic
dimension, you probably want the fix deform
clommand, which will stretch the box and
the atoms in it.


Dear Steve,

thanks for your reply.
But I have faced two problems with the fix deform command :

  1. fix 2 all deform 1 x volume y volume z erate 0.01 units box by using, the both X,Y box length shrinked during increasing the Z box length. this is what is expected from tensile loading subjected to materials. But by running for a great number of time steps just those shrinking and increasing happened. No knecking and fracture were observed. It does not make sense!

  2. The fix deform command is for Periodic boundary condition in 3 dimension. But if I want to study the tensile behavior of a nanowire by non-periodic boundary condition in 2 dimensions and periodic boundary condition in 1 dimension ( boundary s s p ) what will be the appropriate command?

your help will be highly appreciated.


You can apply the fix deform command to a single
dimension. Only that dimension has to be periodic.
The other non-periodic dimensions will respond however
they wish. That is the correct physics.