I want to apply an external pressure on CNT and increase its value until the buckling take place. (when the CNT loses its stability, the buckling take place). I should specify the pressure’s values in each step until the buckling take place.
I am wondering if anyone can help me.
I want to apply an external pressure on CNT and increase its value until the
buckling take place. (when the CNT loses its stability, the buckling take
place). I should specify the pressure's values in each step until the
buckling take place.
what you describe as "pressure" is actually a force on the atomic scale.
now, how to achieve this in a simulation depends on your setup, e.g.
whether you have set up an isolated CNT or are simulating a
1d-periodic system, where the CNT continues to infinite length.
now to achieve the deformation, you have two options as well, a) you
deform the CNT (or the periodic system) by moving atoms (or deforming
the box) and monitoring the averaged forces (or "pressure"). or b) you
can apply an (averaged) force (or pressure) and monitor the
this is all pretty straightforward to do and i am certain, that there
are plenty of publications on the subject matter where people describe
how they have implemented such processes.
in addition to axel’s comment, i’d suggest to run a displacement controlled (axel’s option a) test first. in principle, if you hit a buckling instability in a load controlled test, the system may start to do strange things (huge deformations).
and the other thing is related to the boundary conditions. in the periodic case, it may be hard to interpret the deformation figures, so here i’d start with an isolated CNT and check what effect the fixation on the ends may have on the results.
but generally, the buckling event should be easily identifiable from load-displacement curves.