Hello,
I am new to the field of simulation with LIGGGHTS. I have already done some tutorials and could already successfully import STL files here. I have a problem when importing a very large and complex geometry of a casting (many curves and different diameters).
My goal is to simulate how a sand core (assumed as powder) flows out of the part. Unfortunately I cannot import the desired geometry. The error message says that the STL file is bad mesh. I have tried to create a STL-file with gmesh, but unfortunately the calculation stops after 4 hours. Are there any limits to the complexity of geometry that can be imported into LIGGGHTS? How can a very complex geometry be imported or the STL-file be created?
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Mishal | Mon, 12/08/2025 - 13:04
I've got similar errors in
I've got similar errors in the past. LIGGGHTS does have some geometry commands to reduce certain tolerances and so forth however if you have moving geometry this will often cause issues in your simulation.
To fix the issues I have generally done the following (not sure if you have the software or means to do this though):
-> create the geometry in either GMSH or a FEA software that allows a .stl export based on a tri mesh. Strand7 does this really well
-> I found that Solidworks has the best .stl export, I have used NX and inventor in the past (older versions) and got many errors with geometry since there are not many options for the .stl exports
-> Creating singular components of the geometry, so instead of building one big model create multiple small models that will give you your final result. I found that this simplifies the meshing for the .stl file and you end up with cleaner set of geometry. This fixes issues that you would generally have at intersection points etc..