When I use shrinkwrap (s) in the compression direction, the upper part of the model and the upper of simulation box will deform to be like the attached picture with the increasing strain(a larger strain like 0.14.) That’s why I changed the BC from s to fixed. So, how do I avoid that? Thanks a lot!
SJ
When I use shrinkwrap (s) in the compression direction, the upper part of the model and the upper of simulation box will deform to be like the attached picture with the increasing strain(a larger strain like 0.14.) That’s why I changed the BC from s to fixed. So, how do I avoid that? Thanks a lot!
if you have a free surface, atoms can go where the force drives them to. having a shrinkwrap or fixed boundary does not affect this. the only difference is that with a fixed boundary the atoms will “spill out” of the box and with shrinkwrap the box adapts.
if you don’t want the system to deform, you need to use a different simulation setup.
however, this has nothing to do with LAMMPS and everything with planning your research and designing your simulated systems, and thus it is a discussion you need to have with your adviser/supervisor. i don’t have the time to first figure out what you are trying to do and trying to learn from your simulations and then give you personalized advice. that is actually the job of your adviser.
axel.
Thank you for your reply.
SJ