Hello,
im new to LIGGGHTS and got two questions for further understanding and usage.
1. I wanted to downscale my model and made the particle size smaller (approx. e-03 --> e-06) . This resulted in a neighbor-search error and could be fixed with using nsq instead of bin, but this resulted in a problem with my .stl-mesh. After setting the units from si to micro and customizing the parameters i was able to use the bin-algorithm again. Additionally my simulations are way faster. Why is it like this and did i missed to update a parameter if something like this happens?
2. To simulate my whole problem i would have to use way too much particles, thats why i want to utilize mechanical boundary conditions. I would need to select a plane of particles (which i already wrote a loop for) and link their displacement, like i would do in FEM. Is this possible with a certain command or is there a way around like computing the displacements, calculating and setting the average displacement for all the particles of the plane every timestep?
Thanks in advance,
Alex
wd_whu | Tue, 03/26/2019 - 01:58
fix rigid
fix rigid command might be helpful to you to update particles position, speed and force as a group.
amlk93 | Wed, 04/03/2019 - 10:54
fix rigid
As I understand this command right, I'm just able to turn off interactions from other particles in my desired direction. This way I would link the particles as i want, which is great, but i will additionally set the whole displacement to 0.0 (due to my initial force = 0.0), which is not desired in my case. The displacement on the boundary planes will be induced to a force acting on top of the cube of bonded particles, which is why I don't know the force (will not be constant in time) in the beginning.
Are there any other commands or do I interpret the rigid-command wrong and should chose another option than force or torque?