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MotionView's track builder for a rigid contact soil interaction doesn't keep meshing from HyperMesh.

Hi,

I am trying to simulate a tracked vehicle on a rigid (non-deformable) road in MotionView. I have set up my vehicle using the process given in the Tracked Vehicle Modeling tutorial (link: Tracked Vehicle Modeling) but diverge from the tutorial at the 'Soil Interaction' step (step 3.10).

Here, I use the 'Rigid Contact' option with a meshed flat ground created in HyperMesh, however, the mesh does not carry over to MotionView. Instead, it is replaced by a much coarser mesh, which (I suspect) results in the following error when I try to run the simulation:

"MotionView(General) Error: Contact "TrackLeft Contact Terrain 0" under "Model-Suspension-TrackLeft" references one or more graphics that contain free edges, i.e. the geometry is not closed, or T connections. The graphic(s) in question are: Terrain Graphic. Open shell graphics or graphics with T connections are not allowed in contact simulations."

Please find images of the meshes below:

From HyperMesh - Whole Road

From HyperMesh - Close View

From MotionView - Whole Road

Any help in fixing this issue is appreciated.

Thanks

Find more posts tagged with

HyperMesh

MotionView/MotionSolve

v2023.1

Accepted answers

Christopher_Fadanelli

Hi @VidM ,

For Rigid contact, you will need to input either a CAD or H3D file.

I would suggest to create a simple box geometry, export it as a CAD file (Parasolid preferred).

The soft soil road option needs an rdf that can reference either a .fem or other obstacles.

Best,

Christopher Fadanelli

Christopher_Fadanelli

Hi @VidM ,

You will need to use a 3D surface. You can extrude your surface in Hypermesh and reexport the geometry. To alter the graphics in your wrap system, open each wrap and navigate to the graphics. The first graphic should associate to the Terrain Graphic. You can alter the file used in the Entity Editor.

Best,

Christopher Fadanelli

All comments

Vishvam

Hello @VidM,

I am suspecting the issue is with Units mismatch between Hypermesh and Motionview. The HM .fem file might be in meters, while the default units in MV is in mm. While using the Road Tools there is an option to change this, to use the right units.
Please refer to the below attached slide deck for some best practices in creating and using FEM file for PCD road.

pcd_road.pptx

Also it'd be great if you can attach the .fem file that you are working with. I can check it and get back with the exact issue.

Hope this helps!

Christopher_Fadanelli

Hi @VidM ,

For Rigid contact, you will need to input either a CAD or H3D file.

I would suggest to create a simple box geometry, export it as a CAD file (Parasolid preferred).

The soft soil road option needs an rdf that can reference either a .fem or other obstacles.

Best,

Christopher Fadanelli

VidM

Hi @Vishvam,

Thanks for your response. The unit mismatch does seem like a likely issue. I will convert the HyperMesh model to mm and see if that fixes the problem when I return to the office next week. If not, I'll send the .fem file through.

Thanks

VidM

Hi @Christopher_Fadanelli,

Thanks for your reply. I am currently using a CAD file for the Terrain Graphics File with a flat 2D surface rather than a 3D box geometry. Is this a potential cause of the issue or am I fine to continue using a 2D surface?

Thanks

Christopher_Fadanelli

Hi @VidM ,

Best,

Christopher Fadanelli

VidM

Hi @Christopher_Fadanelli,

Converting the road to a 3D object ended up working for me. Interestingly, the road meshing still didn't carry over from HyperMesh, but the error I was seeing before is gone. I'm guessing this might be because MotionView doesn't need a fine mesh to model a rigid road, so it uses a coarse mesh to save on computational resources.

Thanks again for your help.

VidM

Hi @Vishvam,

I converted my HyperMesh default from m to mm but that didn't seem to affect the error. I was able to get the simulation working by converting the road from a 2D surface to a 3D body as outlined by @Christopher_Fadanelli's comment below.

Thanks for your help, regardless.