Sumaya,
The test scene you are targeting appears to be perfectly doable, but in
order for us to help you, you need to present two things:
1. The error message you gave seems to be the corresponding part of the
code, rather than what got output to the screen... Please provide the
actual error message.
2. Please provide a visual rendering of the simulation scene, before the
crash. Even if it crashes right at the beginning of the simulation, you can
still visualize the initial configuration. This is important and without
visuals, anything we can say is speculative.
Thank you,
Ruochun
On Saturday, December 27, 2025 at 4:33:57 AM UTC+8 sumaya wrote:
> Hello,
>
> I am looking for some suggestions about how to fix my error for the script
> wheelDPsimplified. I have changed the script based on my research
> requirement. My terrain bed is made of glass beads of 3 mm radius, which is
> very small. The beads are a clump of two and purposely, I have overlapped
> them slightly. Now the volume is very small compare to the values provided
> in the demo script. My IXX, IYY, IZZ are also very small and I am not
> currently scaling them. There was issue with the bin size but I have
> temporarily fixed it with the following lines. However, I am currently
> getting unexpected velocity that's crashing the entire system. I have
> played with the terrain properties, step size and HPC sampler spacing but
> nothing seems to fix this problem. Can you please suggest what could be
> possibly happening?
>
> *The error message :*
> DEME_ERROR(
> "System max velocity is %.7g, exceeded max allowance
> (%.7g).\nIf this velocity is not abnormal and you "
> "want to increase this allowance, use SetErrorOutVelocity
> before initializing simulation.\nOtherwise, the "
> "simulation may have diverged and relaxing the physics may
> help, such as decreasing the step size and "
> "modifying material properties.\nIf this happens at the start
> of simulation, check if there are initial "
> "penetrations, a.k.a. elements initialized inside walls.",
>
> * Parameters Output : *
> Current number of clumps: 4216
> Number of total active devices: 1
> User-specified X-dimension range: [-0.45, 0.45]
> User-specified Y-dimension range: [-0.102, 0.102]
> User-specified Z-dimension range: [-0.155, 0.155]
> User-specified dimensions should NOT be larger than the following
> simulation world.
> The dimension of the simulation world: 1.9584000110626221,
> 0.24480000138282776, 0.48960000276565552
> Simulation world X range: [-0.54, 1.4184]
> Simulation world Y range: [-0.1224, 0.1224]
> Simulation world Z range: [-0.186, 0.3036]
> The length unit in this simulation is: 3.5623088680269976e-12
> The edge length of a voxel: 2.3345947397501732e-07
> The initial time step size: 5e-06
> The initial edge length of a bin: 0.012287999153137209
> The initial number of bins: 128000
> The total number of clumps: 4216
> The combined number of component spheres: 8432
> The total number of analytical objects: 2
> The total number of meshes: 1
> Grand total number of owners: 4219
> The number of material types: 2
> History-based Hertzian contact model is in use.
> The solver to set to adaptively change the contact margin size.
> The script crashes shortly after.
>
> *Terrain Properties and Co-ordinates : *
>
> x y z r
> 0.0015 0.0012 0 0.003
> 0.0045 0.0028 0 0.003
>
>
> Glass beads : auto mat_type_terrain = DEMSim.LoadMaterial({{"E", 6.5e10},
> {"nu", 0.245}, {"CoR", 0.926}, {"mu", 0.16}, {"Crr", 0.01}});
>
> // Define the terrain particle templates
> // Calculate its mass and MOI
> float terrain_density = 2500;
> float volume1 = 1.99e-07 ;
> float mass1 = terrain_density * volume1;
> float3 MOI1 = make_float3(1.431e-12, 9.058e-13, 1.282e-12) *
> terrain_density;
>
> HCPSampler sampler(0.025f);
> float sample_halfheight = 0.124;
> float sample_halfwidth_x = 0.42;
> float sample_halfwidth_y = 0.098;
> float offset_z = bottom + sample_halfheight + 0.01f;
>
--
You received this message because you are subscribed to the Google Groups
"ProjectChrono" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion visit
https://groups.google.com/d/msgid/projectchrono/b8c33d1c-461c-4340-8e02-2394b6e839c8n%40googlegroups.com.
