LIGGGHTS® - User Forum

While doing Triaxial test. I have first applied confining pressure (200k) on all 6 wall and then applied fix modify command to modify the target value for top and bottom wall so that additional deviator stress can be applied.

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fix twall_servo all mesh/surface/stress/servo file meshes/sample_4/topwall.stl type 2 com 1.0 1.0 4.0 ctrlPV force axis 0.0 0.0 1.0 target_val -${f_top} vel_max ${vel} kp ${kp1}

run 500000 # run for confinment

fix_modify twall_servo servo/target_val -${f1_top}

Hi all,

I am new to LIGGGHTS and aspire to learn more about using DEM. I am using Windows 10 and have used various methods to install LIGGGHTS. I have managed to build LIGGGHTS with the instructions from Christian:
https://www.cfdem.com/forums/alternative-cmake-build-environment

I am running Cygwin in Windows and was trying to run this command just now:
$ make -f Makefile.shlib auto

But I get the following error:

Hello every one

I am trying to run bonded particle simulation but I am getting an error

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ERROR: Invalid atom_style command (../atom_vec.cpp:75)
--------------------------------------------------------------------------

#bond

atom_style hybrid granular bond/gran n_bondtypes 1 bonds_per_atom 6
#atom_style granular
atom_modify map array
boundary f f f
newton off

#processors 2 1 1

communicate single vel yes

units si

Dear all,

I use LIGGGHTS-PUBLIC 3.8.0 to perform 2D simulations for particle mixing in a rotary drum.

When I use the real coefficient of restitution (0.82) for the mixing material, the real time spent is much higher than I use the default value 0.5 in many other simulation cases.

I recently met this problem when I compiled a pack of source codes, does anyone have any clues what this syntax error is? The application file is called fix evaporate.C in the directory. I want to use this command to calculate the outflow mass rate and delete some particles at a certain rate in my simulation! I added this file into the original SRC directory and recompiled, then the system showed me the information below:

I am attempting to modify the auger tutorial script to use superquadratic particles and I am running into the following error: Invalid attribute in dump custom command (../dump_custom.cpp:146). I believe the error is related to the dump syntax. Any help and suggestion is greatly appreciated. I have attached the input file and the relevant geometry folder.

Hello everyone;
I am trying to validate my numerical model with previous model. Therefore, I am trying to generate 6614 particles into the region 0.028 x 0.0054 x 0.0576, which the particle bed porosity is 0.39. However, I cannot obtain the same result.
LIGGGHTS inserted less particles than requested and my porosity is much higher than model in previous study

Hi Everyone!

When i use the "compute pair/gran/local" using the following:

compute cpgl all pair/gran/local pos id force contactArea
dump dmp_cpgl all local 1000000 output/fc/cpgl*.dump c_cpgl[1] c_cpgl[2] c_cpgl[3] c_cpgl[4] c_cpgl[5] c_cpgl[6] c_cpgl[7] c_cpgl[8] c_cpgl[9] c_cpgl[10] c_cpgl[11] c_cpgl[12] c_cpgl[13]

The above works perfect for me!

However, if i would like to know the coordinates of the contact point at which the force is calculated, i need to use the following:

Hello everyboday;
I am working on irregular particles. I clumped the particles together by the fix multisphere command. I use Paraview to visualize the irregular particles but the rendering image is not good. It is hard to see the shape of particles. I am wondering if there are plugin of Paraview or other programs that can help me to visualize the shape better?
Thank you

Is there a way to have a group of particles being skipped by collision detection and locked in place, ideally while reducing the computation time.

A simulation that I'm running involves filling a tall cylinder with particles and I want to ignore the majority of them and only freeze a certain distance from the top for the next layers.

Simulating the entire stack is not feasible computation time wise on my desktop.

I haven't been able to find functionality like this in the documentation

Thanks,
Alex