Thank you! Enjoy building the robot. It's an opportunity to learn at lot. 🤓

Thank you for your work on this project! 🙏

Thank you!

You wish

No, that is me when I see the ladies

As a lady, I cannot confirm

Hi Mani, I used Yade (yade-dem.org/doc/), which, however, does not support splitting / crushing particles into smaller particles, as far as I know. I remember that LIGGGHTS was also a good solver (github.com/CFDEMproject/LIGGGHTS-PUBLIC), but I do not remember, if the open-source version supports the previous feature. I am aware that Paul Cleary has been working on it. I think that this feature is also available in the commercial solver Rocky (rocky.esss.co/).

Thank you! Yes, I used the USER-SMD package in LAMMPS. This package implementes SPH in the LAMMPS framework. Everything is explained in detail in my PhD thesis: orbi.uliege.be/handle/2268/245441 (starting on page 273).

Hi Carlos! Thank you for your kind comment. I have no experience in crushing silicon rich rocks for agricultural use in particular but I can tell you the following: - the finer the grinding of the rocks, the higher their active surface and the more nutrients can probably be provided to the soil; - the finer the grinding and the harder the material (content of SiO2), the more energy (money) is required; - the fine grades (powders) are usually obtained by ball milling. I do not know of any other process that could result in such fine grades, while being sufficiently scalable (vertical roller mills are only cost-efficient at big scale). To make sure that my comments are correct, I took a quick look at the scientific literature [1]: "Whole rocks were crushed in a jaw crusher and a ball mill" in a context similar to yours. Thus, ball mills seem to be used. Jaw crushers are required when the rocks are still very coarse., i.e. before ball milling. I hope that I could help you. Feel free to comment, if my explanations are not clear enough. [1] Bakken, Gautneb, Sveistrup, Myhr (2000), Crushed rocks and mine tailings applied as K fertilizers on grassland, Nutrient Cycling in Agroecosystems, 56(1), 53-57.

Thank you! No, it was no built-in feature, but programming. Initially, I created a surface mesh file, i.e. a list of vertices, edges and triangular facets, via GMSH. This mesh was loaded in the DEM solver. During the simulation, a wear value was computed for each facet. These values were written to a file at the end of the first DEM computation. Then, I loaded this file and the mesh into Matlab (or a Python program, ...) and I displaced the vertices normally to the surface by an amount, which is proportional to the local wear. Just to be clear, this was done by literal programming, i.e. by implementing the mathematical equations to displace nodes along a given direction, ... Afterwards, I wrote the updated mesh again to a file, which is loaded in the next DEM simulation and so on. Thus, some programming skills in C++, Python and Matlab were required. I hope this helps.

Thanks for the answer. Yes I was expecting this. Would it be possible for you to share any links that could introduce me to such topics, for examples, reading mesh files in matlab etc. Thanks for your help :)

The answer depends very much on the specifics, here for instance the format of the mesh file. I think that the best way to solve this problem would be to take a general programming course first, if you do not have any knowledge about programming (I would suggest about Python), and then searching online for the specific solution, i.e. to understand the structure of the mesh file. Since this solution depends on your choices (solver, file formats, ...), I can not provide you any links. But they are certainly not too hard to find via Google.

The interaction is purely normal by a Hertzian repulsion. More details can be found here (page 28): lammps.sandia.gov/doc/PDF/SMD_LAMMPS_userguide.pdf

Thank you for the document! : )