LIGGGHTS® - User Forum

hello LIGGGHTS Experts,

I have to compute stress and strain for particles.
I tried calculate stress by command:
fix stress all ave/euler nevery 1000 cell_size_relative 4.5 parallel no
and
collected the result by:
dump damp all custom 1000 post/dump*.liggghts id f_stress
but I recived following error:
ERROR: Dump custom fix does not compute per-atom info (../dump_custom.cpp:1383)

How to correctly dump this results?
Can I calculate the strain and stress for a particles in other way?

Best wishes,
Agnieszka

Hello,
I have problem when building liggghts. the makefile.user have been changed as mentioned in the installation document. I have not compilled VTK seperately. So i did the following changes in makefile.user:

USE_VTK = "ON"

VTK_INC_USR=-I/home/liggghts/vtk/include

VTK_LIB_USR=-L/home/liggghts/vtk/lib

So this should automatically download and install VTK. But i am getting the following error.

Hello,

I am very new to LIGGGHTS and I just recently began using it through an Ubuntu environment which I am also new to. I am attempting to run the command:
"mpirun -np 4 lmp_auto -echo both < in.vel2.txt"
and I received the error:
"lmp_auto: error while loading shared libraries: libvtkCommonCore-6.2.so.6.2: cannot open shared object file: no such file or directory"
which is repeated four times before terminating.

I got this error

# Preliminaries
units si
atom_style sphere
boundary f f f
newton off
communicate single vel yes

# Domain
region reg block -0.320 0.320 -1.960 1.460 -0.290 0.335 units box
create_box 3 reg
Created orthogonal box = (-0.32 -1.96 -0.29) to (0.32 1.46 0.335)
1 by 1 by 1 MPI processor grid

### Setup

Hello everyone,

I am conducting a triaxial test for soil. I am running 2 simulations for this triaxial test . In the first simulation the particles were inserted and then consolidated with a confining pressure of 500 kPa. At the end of the this simulation, a restart file is generated.

Dear all,
I am a new LIGGGHTS user. I would like to do run a case in which two particles with an initial velocity collide with each other.
I am wondering if it is possible in LIGGGHTS to give an initial velocity to the particles or not?
Thank you in advance.
Shadi

Hello
Can anybody help me in calibrating cohesionEnergyDensity. I dont know how to calibrate cohesionEnergyDensity for a material.
Is there any standard procedure for adjusting cohesionEnergyDensity value.

Hi,
I am trying to install LIGGGHTS in a gnu server. When I trying to create makefile.user using command 'make auto' its not creating. As it is required to set the vtk path. Can anyone please tell me what am I missing?

Hello Guys,

I'm new to Liggghts. I created code from Particle size distribution, but I'm not understanding how to make it in group and insert particles randomly in cylinder disc.

Please help me.. thank you

Hello, the code sends me the following error:
ERROR: Fix massflow/mesh (id mass): need to change 'vec_side', it is currently in or to close to the mesh plane (../fix_massflow_mesh.cpp:245)
In the documentation of liggghts it states:
vx, vy, vz = vector components defining the “outside” of the mesh.

Why does the program indicate that error? I have tried with several vectors that are not "close" to the counter mesh
thank.