LIGGGHTS® - User Forum

Hi,
I have some questions regarding the implementation of the “cohesion_model_easo_capillary_viscous.h” (or for that matter washino) which I would really appreciate your reply to help me understand the algorithm and to properly apply the code. My main questions are with regards to the criteria to evaluate the three possible cases of no-bridge, active, breakage of the liquid bridge force.
Thank you for your time and consideration.
Ali

Dear all,

Dear all,

I am a little confused about the usage of the variable type of f_a and ${a}. To give an example, when I use "fix a all mesh/serface/stress/servo ...", I want to obtain the displacement of the servo wall, thus I use "variable loct euqal f_a[9]-0.1" where 0.1 is the original of the servo stl wall. When I want to applied this variable in another command (e.g. fix b all mesh/surface/stress ... move 0. 0. ${loct}), the ERROR message shows: invalid fix ID in variable formula.

When trying to create bonds in "LIGGGHTS-WITH-BONDS" , I get the following error:

creating bond btw atoms 726 and 1741 (i has now 12 bonds) at step 1001
creating bond btw atoms 726 and 1743 (i has now 13 bonds) at step 1001
ERROR on proc 0: New bond exceeded bonds per atom in fix bond/create (../fix_bond_create_gran.cpp:485)

Dear all,

I am using command "read_restart" to restart my simulation and used the same servo wall command as the original code which is applied to create the restart file (shown below).

"fix topwall all mesh/surface/stress/servo file meshes/topwall.stl type 2 com 0. 0. 0.1 ctrlPV force axis 0. 0. -1 target_val 300 vel_max 0.03 kp 1"

Dear All,

I would like to create a gaussian or log-normal particle size distribution, I mean for the particles radii. Unfortunately, I cannot find anything in the documentation, even though someone implemented a "radius gaussian number" in the "in.liggghts_init" (input command file for DEM). For example:

Dear all,

I am doing a triaxial compression test using LIGGGHTS. First, I applied six servo controlled wall using command: fix mesh/surface/stress/servo to execute a confining pressure on a cube soil specimen. After this process, I want to execute a constant velocity on the walls instead of a target force on the servo walls. This means I may need to change the servo controlled wall to velocity controlled wall.

Hi!

I have compiled liggghts with make clean-all and then make auto in order to get the latest version of liggghts (3.7). The compile process end without problems but then the system doesn't recognize liggghts, in other words, when i type "liggghts" in the terminal, i get the following message:

Software «liggghts» Is not installed. You can install it by typing:
sudo apt-get install liggghts

Dear all,

I am coding a triaxial compression test using LIGGGHTS and want to apply the command: Fix mesh/surface/stress/servo. I set my servo wall as follows:

Hello all,
I am trying to write a script that will read in values from a datafile and then use that data to preform calculations on each capillary bridge between particles in a fluid bed. I am having trouble, however, employing my newly written module. I have the following line in the header file : PairStyle(cap/vis/field,CapViscHist) and have compiled lammps to include my .cpp and .h files, but I receive and unknown pair_style error when I try and run the input file. Any help would be much appreciated!

Carter Rhea