set different boundary conditions for nanobeam

Dear lammps users,

I’m trying to simulate nanobeam with different boundary conditions(clamped-clamped, clamped-free and pinned-pinned).
For clamped boundary, I just group the regions and do simulations without the regions, which I think is clamped. Otherwise I think I could set force as null null null or 0 0 0.

For pinned boundary conditions, I am not really sure how to do. Should I setforce as 0 in horizontal and vertical direction and null in z direction, which allows rotating.

Thanks very much

Hi everyone,

Just wondering if there is someone who can give me a hand on that.I am not sure if my thoughts are correct.

A lot of thanks

For clamped-clamped, you could define small regions at the ends of your nanobeam and use setforce to prevent all movement of those atoms (a material in a clamp can’t move, right?). For clamped-free, you would have one region at one end of the nanobeam which prevents those atoms from moving. For pinned-pinned, it sounds reasonable to me to set groups at the corners of your nanobeam and then use setforce as you describe.

Hi Will,

Thanks for your reply, that explains it.

Warm regards