Deform command

Dear all,

I am doing a crack simulation and would want to know if there is any difference between using the method which is given in the example and using the deform command.

I did such a simulation which looks fine but I dont know if the method used is correct.

I am deforming in the y direction and have used s p p boundaries.

The same simulation using velocity method I ramp the velocities in the top and bottom atom groups . I use s s p boundary condition.

thanks a lot.


They are different. Fix deform changes the box and you
have the option to deform some or all of the atoms
with the box. If you only deform a wall of atoms at the
end of the box, you would be doing something similar
to the example. But if you deform all the atoms
it’s very different.



But what would be the best way to simulate a crack?

The one which imparts velocity to groups ?

I think you should let atoms near
the crack move freely, and only control
the positions/velocities of atoms far
from the crack.