Thanks for your email. You say “such as sand, snow, or grass”. I doubt that there is any deformable tire model in the world that will allow you to gauge its interplay with grass. Snow is hard too, but more plausible. Sand is possible in Chrono, as are other homogenized terrain types, e.g., silt, clay. You’ll need reasonable material properties to capture these soil types. This is not trivial. That being said, in many cases, for off-road mobility one can do ok with rigid wheels. The wheels can have features (lugs, tread pattern, etc.) – the sim is much faster in that case (compared to deformable tires).
We’ll send you in this thread an example of how to combine deformable terrain (CRM-based) and vehicle dynamics, when the vehicle uses deformable tires. The tires are modeled using ANCF shell elements. This relies on GPU computing, you will need an NVIDIA GPU to run the sim. Hopefully that’ll happen early next week. Dan --------------------------------------------- Bernard A. and Frances M. Weideman Professor NVIDIA CUDA Fellow Department of Mechanical Engineering Department of Computer Science University of Wisconsin - Madison 4150ME, 1513 University Avenue Madison, WI 53706-1572 608 772 0914 http://sbel.wisc.edu/ http://projectchrono.org/ --------------------------------------------- From: projectchrono@googlegroups.com <projectchrono@googlegroups.com> On Behalf Of juju Sent: Friday, August 1, 2025 8:05 AM To: ProjectChrono <projectchrono@googlegroups.com> Subject: Re: [chrono] HMMWV with ANCF tire Hello, I would like to study the interactions between a tire and various terrain obstacles while the vehicle is in motion. I saw that several tire models are available, such as TMeasy, Pacejka02, ANCF, and Reissner. According to the documentation, force-based tire models (e.g., Pac02, TMeasy) cannot be used with soft obstacles or deformable terrain (such as sand, snow, or grass). On the other hand, the ANCF tire model is specifically designed to accurately capture soil–tire interactions. Therefore, for my use case, the ANCF tire model seems to be the most appropriate choice. I tried using it with the demo script demo_VEH_SCMTerrain_WheeledVehicle.cpp, but after just a few milliseconds of simulation, the tire explodes, and the simulation is extremely slow (even with SetNumThreads set to the maximum number of available threads). I’m wondering if anyone has successfully run the ANCF tire model with the HMMWV (or other vehicles) in a simulation that utilizes hardware resources efficiently (CPU, GPU, etc.). Thank you for your help! 😊 Le jeudi 31 juillet 2025 à 19:43:55 UTC+2, Dan Negrut a écrit : Hi there - can you please describe what you try to accomplish? We might be able to help with the ANCF tire model, but before that, please tell us what you want to accomplish since there might be easier paths forward. ANCF is heavy duty. Dan --------------------------------------------- Bernard A. and Frances M. Weideman Professor NVIDIA CUDA Fellow Department of Mechanical Engineering Department of Computer Science University of Wisconsin - Madison 4150ME, 1513 University Avenue Madison, WI 53706-1572 608 772 0914<tel:(608)%20772-0914> http://sbel.wisc.edu/ http://projectchrono.org/<https://urldefense.com/v3/__http:/projectchrono.org/__;!!Mak6IKo!JSDXJGQygVKiAauWzjHvBuoag6QwX4RYazzFgeUhHoZ0yDuDP7k6mOzrfl1Br70yqS1nGYMZXSetmqNA$> --------------------------------------------- From: projec...@googlegroups.com <projec...@googlegroups.com> On Behalf Of juju Sent: Thursday, July 31, 2025 11:41 AM To: ProjectChrono <projec...@googlegroups.com> Subject: [chrono] HMMWV with ANCF tire Good morning, I am a PhD student working on off-road vehicle navigation, and I found ProjectChrono very interesting for testing my algorithms. I would like to use the HMMWV vehicle with ANCF tires for more realistic behavior. However, when I run the demo script demo_VEH_SCMTerrain_WheeledVehicle.cpp with TireType::FEA, the simulation becomes unstable and extremely slow. It runs fine with other tire types. Does anyone have a demo script using HMMWV with ANCF tires that is both stable and performs well (accelerated and reliable)? Thank you very much! -- 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 projectchron...@googlegroups.com. 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