Thank you for the tutorial. Would you know how to do this but instead with velocity measurements for let's say, a single particle or for all particles and then plot it over time? Thank you in advance!
I would like to thank you for nice video and simple explanation. Could you please explain how we can find volume fraction for settled particle in silo( in general how to find the volume fraction of generated particle). Thanks in advance Regards
Hey Yassin, thanks for your feedback. You simply can do a measurement geometry in paraview using the clipping tool. From that you get the defined volume which value you know. Now you have to sum up the individual volumes of the particles. For that you can use the python programmable filter or you export the timestep as a *.csv datafile out of Paraview and open it in Matlab or Excel. Doing that you get the volume of your region and the particle volume. The fraction is what you what to know.
Hey Sam, thanks for sharing. In the second part we will show a method to analyse the the mass or particle measurement by mesh. This method is very similar to the handling of forces.
i used the following and got only zeros in the csv file how can i calculate the mass and number of particles with different types thanks region measureinsertion block 0 0.15 0.7 0.9 -0.3 0.3 units box group g1 type 3 variable absinsmass equal mass(g1,measureinsertion) variable absinsNop equal count(g1,measureinsertion)
Hey Pain, is the simulation running without an error to the end? Is there any error massage in the log file? Else I would assume that the error might be somewhere else. Have you included new 3 types of particles during create command?
Hey Frost, thanks for your feedback. in general you can use the command for volume fraction calculation. But if you define a region you have to be aware that in liggghts the particle is counted as soon the center of the particle is inside this region. If you make a cube and fill it top the top ending with a smooth surface, you can get a quite accurate volume fraction with the method. Cheers and stay safe, Engineerdo
If we had 2 or 3 type of different particle types and we need to find how much of each type inside the container i tryied adding a gŕoup and replaced all with the group nam in variable line got 0 any tips thanks
Hey pain, in general it sounds like the right way. Maybe something went wrong with definition of the types? Have you also double checked, that you are measuring in the correct region? Cheers, EngineerDo
@@borancam7426 hi i used two types with the group command and used the set command to define the groups and then dumped them using the print command like the video
Thanks for your videos. I am new to liggghts. Your videos are really helping. Please do you have an idea on how to simulation triaxial test in liggghts
Hey Derrick, thanks for your feedback. We are allways happy to help people to solve their problem. For the triaxial test you will propably have to take a look to this command in the manual: fix mesh/surface/stress/servo command Here you can controll the movement of the walls bei a forces.
@@engineerdo6568 Thanks for your response. I have checked the function and i have applied it. The problem i am facing is how liggghts is calculating the stress in the system. I want the overall stress state of the system at every time step but i get stress matrix for each particle in the system at every time step. And also how to calculate the volume change and void ratio of the system during compression
Thank you for the tutorial. Would you know how to do this but instead with velocity measurements for let's say, a single particle or for all particles and then plot it over time? Thank you in advance!
I would like to thank you for nice video and simple explanation.
Could you please explain how we can find volume fraction for settled particle in silo( in general how to find the volume fraction of generated particle).
Thanks in advance
Regards
Hey Yassin, thanks for your feedback. You simply can do a measurement geometry in paraview using the clipping tool. From that you get the defined volume which value you know. Now you have to sum up the individual volumes of the particles. For that you can use the python programmable filter or you export the timestep as a *.csv datafile out of Paraview and open it in Matlab or Excel. Doing that you get the volume of your region and the particle volume. The fraction is what you what to know.
@@engineerdo6568 Thanks a lot.
@@yassinalkassar9876
I see a lot of applications for this video.
Nice to know, I think this could be useful for many applications. I already used the csv output to get the total force and momentum.
Hey Sam, thanks for sharing. In the second part we will show a method to analyse the the mass or particle measurement by mesh. This method is very similar to the handling of forces.
i used the following and got only zeros in the csv file how can i calculate the mass and number of particles with different types thanks
region measureinsertion block 0 0.15 0.7 0.9 -0.3 0.3 units box
group g1 type 3
variable absinsmass equal mass(g1,measureinsertion)
variable absinsNop equal count(g1,measureinsertion)
Hey Pain,
is the simulation running without an error to the end? Is there any error massage in the log file? Else I would assume that the error might be somewhere else. Have you included new 3 types of particles during create command?
Hello. Thanks for this - very useful. Is it possible to provide a link to the input decks?
Thank you very much it's really helpful
Hey Volkan! Glad it was helpful!
Thank you!!! It's relally enlighting. Can this be used to calculate the volume fraction of particles?
Hey Frost, thanks for your feedback.
in general you can use the command for volume fraction calculation. But if you define a region you have to be aware that in liggghts the particle is counted as soon the center of the particle is inside this region. If you make a cube and fill it top the top ending with a smooth surface, you can get a quite accurate volume fraction with the method.
Cheers and stay safe, Engineerdo
@@engineerdo6568 thank you!!!
If we had 2 or 3 type of different particle types and we need to find how much of each type inside the container i tryied adding a gŕoup and replaced all with the group nam in variable line got 0 any tips thanks
Hey pain, in general it sounds like the right way. Maybe something went wrong with definition of the types? Have you also double checked, that you are measuring in the correct region?
Cheers, EngineerDo
@@engineerdo6568 i solved the problm thanks for the content and if possible do a video about expanding liggghts with new add ons and recompiling it
@@painrikosu1017 hi how did you solved your issue? I have the same problem
@@borancam7426 hi i used two types with the group command and used the set command to define the groups and then dumped them using the print command like the video
Thanks for your videos. I am new to liggghts. Your videos are really helping.
Please do you have an idea on how to simulation triaxial test in liggghts
Hey Derrick, thanks for your feedback. We are allways happy to help people to solve their problem.
For the triaxial test you will propably have to take a look to this command in the manual:
fix mesh/surface/stress/servo command
Here you can controll the movement of the walls bei a forces.
@@engineerdo6568 Thanks for your response. I have checked the function and i have applied it. The problem i am facing is how liggghts is calculating the stress in the system. I want the overall stress state of the system at every time step but i get stress matrix for each particle in the system at every time step.
And also how to calculate the volume change and void ratio of the system during compression