fix continuum/weighted

Submitted by hosseinhaeri on Tue, 08/04/2020 - 04:31

Hello guys

I wrote this code :

atom_style granular

#atom_modify map array

boundary p p p

newton off

communicate single vel yes

units si

region reg block -0.005 0.005 -0.005 0.005 0.0 0.03 units box

create_box 2 reg

neighbor 0.002 bin

neigh_modify delay 0 contact_distance_factor 1.5

hard_particles yes

fix m1 all property/global youngsModulus peratomtype 2.6e7 6.9e13
fix m2 all property/global poissonsRatio peratomtype 0.1 0.1
fix m3 all property/global coefficientRestitution peratomtypepair 2 0.7 0.6 0.6 0.8
fix m4 all property/global coefficientFriction peratomtypepair 2 0.24 0.24 0.24 0.24
fix m5 all property/global RollingFriction peratomtypepair 2 0.1 0.1 0.1 0.1
fix m6 all property/global SlidingFriction peratomtypepair 2 0.166 0.166 0.166 0.166
#fix m7 all property/global characteristicVelocity scalar 2.0

pair_style gran model hertz tangential history

pair_coeff * *

timestep 0.00001

fix gravi all gravity 9.81 vector 0.0 0.0 -1.0

fix xwalls1 all wall/gran model hertz tangential history primitive type 2 xplane -0.002 shear x 0.001 shear y 0.001 shear z 0.001 contact_area & projection store_force yes store_force_contact yes store_force_contact_stress yes
fix xwalls2 all wall/gran model hertz tangential history primitive type 2 xplane 0.002 shear x 0.001 shear y 0.001 shear z 0.001 contact_area & projection store_force yes store_force_contact yes store_force_contact_stress yes
fix ywalls1 all wall/gran model hertz tangential history primitive type 2 yplane -0.002 shear x 0.001 shear y 0.001 shear z 0.001 contact_area & projection store_force yes store_force_contact yes store_force_contact_stress yes
fix ywalls2 all wall/gran model hertz tangential history primitive type 2 yplane 0.002 shear x 0.001 shear y 0.001 shear z 0.001 contact_area & projection store_force yes store_force_contact yes store_force_contact_stress yes
fix zwalls1 all wall/gran model hertz tangential history primitive type 2 zplane 0.000 shear x 0.001 shear y 0.001 shear z 0.001 contact_area &
projection store_force yes store_force_contact yes store_force_contact_stress yes

region bc block -0.002 0.002 -0.002 0.002 0.0 0.02 units box

fix press all mesh/surface file surf_.0045.stl type 2 scale 0.5 move 0.0 0.0 0.024

fix pts1 all particletemplate/sphere 15485863 atom_type 1 density constant 1631 radius constant 0.0005
fix pts2 all particletemplate/sphere 15485867 atom_type 1 density constant 1631 radius constant 0.0006
fix pdd1 all particledistribution/discrete/numberbased 86028157 2 pts1 0.8 pts2 0.2

fix ins all insert/pack seed 32452843 distributiontemplate pdd1 vel constant 0.0 0.0 -0.3 &
insert_every once overlapcheck yes all_in yes particles_in_region 50 region bc

fix integr all nve/sphere

fix str1 all continuum/weighted kernel_radius 0.0018 compute stress
fix str2 all continuum/weighted kernel_radius 0.0018 kernel_type Gaussian compute stress_strain

#compute peratom all stress/atom

compute rke all erotate/sphere
thermo_style custom step atoms ke c_rke vol
thermo 1000
thermo_modify lost ignore norm no

dump dmp all custom/vtk 800 post/newModels_*.vtk id type x y z ix iy iz vx vy vz fx fy fz omegax omegay omegaz radius ???? ???? ???? ????

dump dmpBOX all mesh/stl 800 post/Disc*.stl

run 40000
unfix ins

fix zwalls2 all wall/gran model hertz tangential history primitive type 1 zplane 0.029
fix meshwalls all wall/gran model hertz tangential history mesh n_meshes 1 meshes press
fix move2 all move/mesh mesh press linear 0.0 0.0 -0.25

run 7000

unfix move2

fix move2 all move/mesh mesh press linear 0.0 0.0 -0.001

run 4000

it is a stress analysis code but in continuum mode , I do not how to dump the fix continuum/code , I knew that there are some information at the end of this page :
https://www.cfdem.com/media/DEM/docu/fix_continuum_weighted.html

but I do not know how to write it !!!

Best Regards
Hossein

Forums:

Zorica Ristic | Tue, 08/25/2020 - 11:03

Hi Hossein,

if you want to output stress in the mesh, then just follow the example from the documentation: fix 1 all continuum/weighted kernel_radius 0.01 compute stress
Here you've declared the 'stress' compute within the fix with an ID '1' and you treat it exactly as what it is is: a compute. So, now you should declare variables and equalize them to the components of the result of the 'stress' compute (c_stress[1]...) and then use those variables in the dump command.
It is the same with strain and stress_strain computes.

All the best,
Z

hosseinhaeri | Mon, 12/14/2020 - 10:57

the command that you mentioned is for stress per atom test c_stress[1]
For this code in the documentation is F_[] something like this and we can not dump it

HosseinHaeri

hosseinhaeri | Sat, 02/06/2021 - 00:57

Hello

yes , I have problem with these f_stressTensor_[i] commands !
when you run the program you see nothing ! it is really strange , It is really easy to get stress and strain curve but I do not know why nobody shared any idea
about this important command !!!

Thanks

HosseinHaeri