Adams Car - Recent Threads

RE: ADAMS/Car Leaf Spring Editor: Using Inputs based on Design Height Geometry

Rishikesh Mokashi — Mon, 17 Aug 2026 08:02:44 GMT

The Leaf Spring Editor expects the X and Z coordinates to represent the leaf spring in its free (unloaded) state. During the makeleaf process, the spring is taken through three stages: free shape → rise-to-curb position (where the bushings are zeroed) → design position.

If the geometry entered in the editor already represents the spring at design height, the model effectively starts from a pre-deflected condition. When vehicle weight is subsequently applied, the spring will deflect even further, resulting in additional flattening.

Note- The Rise to Curb and Reference Marker to Leafpack parameters are only used to define the preload sequence. They do not convert the input geometry from one load condition to another.

Possible approaches:

Estimate the free shape geometry by offsetting the CAD Z-coordinates based on the expected deflection under the design load. This requires a reasonable estimate of spring stiffness and applied load.
Adjust the Reference Marker height by specifying a slightly higher Z-value at the design-load condition. This can help compensate for the additional deflection and may be refined through a few iterations until the desired loaded shape is achieved.

ADAMS/Car Leaf Spring Editor: Using Inputs based on Design Height Geometry

jsph_inc — Wed, 05 Aug 2026 13:23:04 GMT

Hello,

I am using the Leaf Spring Editor to create a leaf spring in ADAMS/Car. I have CAD of the leaf spring in the design height. CAD of the leaf spring in the unloaded position is not available.

If I use this CAD for the leaf X-Z locations, is there a way to account for it being in design height (ADAMS expects these locations to be the unloaded position)?

I've been trying to compensate for this through the "Rise to Curb" and "Reference Marker to Leafpack" values but no luck so far. After equilibrium the leaf springs have flattened which is not realistic.

Thanks for any help!

CRGE road in Adams CAR

Vojtech Brychta — Thu, 02 Apr 2026 04:17:55 GMT

Hello,

is it possible to use CRGE (CRG encrypted) in Adams CAR?

If so, how to go about it?

Thanks a lot!

Sincerely,

Vojtech

RE: CRGE road in Adams CAR

Alexis Del Rio — Thu, 02 Apr 2026 04:46:22 GMT

yes, we can provide these. I will contact you via email to discuss.

Thanks,

Alexis

RE: CRGE road in Adams CAR

Vojtech Brychta — Thu, 02 Apr 2026 04:42:14 GMT

Hello Alexis,

thanks for a quick feedback! It's the Idiada PG package from Altair. I noticed I have a licence to use these road files. But obviously, I'd like to use them in Adams. Is there a way to obtain these roads for Adams?

Thanks.

Vojtech

RE: CRGE road in Adams CAR

Alexis Del Rio — Thu, 02 Apr 2026 04:33:13 GMT

Hi Vojtech,

As you mentioned crge is an encrypted crg file from Altair. They 'convert' to crge because we were first encrypting crg files without needing to change the extension.

Unfortunately, we don't read .crge files in AView or ACar (same way Altair doesn't read our encrypted method). Instead we use our own encryption method. What proving ground is this?

thanks,

Alexis

RE: Performance when running complex analysis with Ftire and flex bodies

Rishikesh Mokashi — Thu, 26 Mar 2026 02:15:56 GMT

Hi Vojtech,

I would expect the HHT to be faster, however since you mentioned the sim failed it would be good to investigate the model to check what the reason behind this is. Please feel free to contact support by logging a request.

Regarding solver settings, you may want to test with the following settings

GSTIFF + Original corrector

Error seems very loose, you may want to tighten this say1e-02 to start with

Hmax: 0.005

Regards,
Rishi

Performance when running complex analysis with Ftire and flex bodies

Vojtech Brychta — Tue, 17 Mar 2026 04:53:49 GMT

Hello, I need to run a long analysis of a vehicle running on a rough road. I need to use Ftire + relatively large flex body (20GB). The obvious issue is that the computational time gets out of reasonable timeframe. However, the CPU load remains very low. I have then following questions:

What steps should I take to improve the performance when using FTire and Flex bodies?
Is there a way to fully utilize the performance my computer provides?

Thank you.

SIncerely,

Vojtech Brychta

RE: Performance when running complex analysis with Ftire and flex bodies

Vojtech Brychta — Thu, 26 Mar 2026 01:58:42 GMT

Hello Rishi!

thanks for the information!

So far I have done following:

- reduced the visualization of the MNF to lower the size of MNF (from 20GB to ~8GB) - doesn't really help with the calculation speed

- run a small sample at reduced sample rate and then disabled modes by energy tolerance

- run the analysis multithreaded in batch mode, keeping everything in the same place.

The run is sped up considerably while maintaining similar results. The dynamic solver setting is following:

Integrator GSTIFF (tried HHT, the driver wasn't able to follow a trajectory so the sim failed - not sure what's the reason)

Formulation I3 (tried SI2 - didn't see any impact on performance)

Error - 0.4

Hmax 1e-3

Kmax 6

Maxit 10

Any suggestions on the solver settings ?

Thanks again!

Have a nice day,

Vojtech

RE: Performance when running complex analysis with Ftire and flex bodies

Rishikesh Mokashi — Thu, 26 Mar 2026 01:30:34 GMT

Hello Vojtech

Could you please let us know what are the solver settings and integrator that you are using? Here are some general suggestions-

Turn off FTire’s separate animation window if it is on (e.g., SEPARATE_ANIMATION…0 ) and run in batch/no-GUI.
Reduce flex modes / use better reduction (CMS) to shrink the 20 GB model, and lower rough-road resolution to only what’s needed for your target frequency range.
Set a sensible thread count (NTHREAD ≈ number of physical cores) and, if using CPU affinity, ensure the thread count does not exceed the number of cores in MSC_ADAMS_THREAD_AFFINITY_SET0.
Make sure you have enough RAM so the run doesn’t page to disk, and keep model/temp files on a fast local SSD.

Regards,
Rishi

RE: Problem with suspension model

Vojtech Brychta — Tue, 17 Mar 2026 04:47:44 GMT

Hello, what is the setting of the analysis you're trying to run?

As suggested bellow, try to run a dynamic event, it sometimes shows you what could be wrong.

Sincerely,

VB.

Problem with suspension model

Riccardo Biasi — Fri, 27 Feb 2026 12:29:37 GMT

Hello,
I have been using Adams Car for several weeks now, specifically for my university thesis involving our Formula Student racing team.
I started with the Formula Student model provided in your webinars and modified it to reflect our car's specific decoupled suspension layout.
However, I have encountered a persistent error that is preventing me from proceeding with my simulations.
Whenever I attempt to run a simulation, the system returns the message that you can see on the attached photo.
I understand this is likely a model configuration issue. Since I am relatively new to Adams Car, I am having trouble locating the root cause of the error and determining the necessary steps to resolve it.
Could you please provide some guidance or assistance on how to troubleshoot this specific error?
Thank you for your time and help.
Best regards,

Riccardo Biasi

nexus.hexagon.com/.../2870.fsae_5F00_decupling.zip

RE: Problem with suspension model

Jesper Slattengren — Tue, 03 Mar 2026 09:02:58 GMT

I don't think the problem is in the template, that looks pretty normal. More likely it is in your model data.

The error message simply says that the static solution was not successful. You can try to increase the max number of iterations from 25 t0 250, that might help.

But most likely your spring data is wrong. Probably the preload is not correct, that is the most common problem.

Try to run the Dynamic suspension event, increasing the motion of the wheel from -20 mm to +20 mm. This can help you pinpoint the error. Bit there is a chance that this won't work either because it probably will try a static solution first.

RE: Problem with suspension model

MC202509189142 — Fri, 27 Feb 2026 13:09:05 GMT

Thread moved from How to use Nexus Community

RE: Adams/Car: Guidance on Steering Gear Box Integration in Adams Model

Jesper Slattengren — Mon, 05 Jan 2026 07:10:19 GMT

Have you looked at the steering models that are included in the Adams Car Truck plugin? They are not very advanced, but is a good starting point.

Adams/Car: Guidance on Steering Gear Box Integration in Adams Model

Santhosh Solomon — Mon, 05 Jan 2026 03:37:48 GMT

Hello everyone,

I’m seeking a methodology or template to incorporate a detailed steering gear box into a commercial vehicle Adams model.

Additionally, I would appreciate support in calculating steering effort, including considerations for power assistance.

Thank you in advance for your help!

RE: Adams/Car: Guidance on Steering Gear Box Integration in Adams Model

Rishikesh Mokashi — Mon, 05 Jan 2026 04:34:17 GMT

Hi Santhosh

Please contact the Adams support team with your requirements and they would help you further.

Regards,
Rishi

RE: Shell Geometry is Very Large?

James Parkus — Thu, 18 Dec 2025 15:47:55 GMT

I found a few errors when I tried to load the .adm file using the instructions for debugging in this Knowledge Center article (AEI-Initialize: Error in initialization during Adams/Matlab co-simulation). It spit out a bunch of errors with the updated contacts and recently added clearances. Looks like I made a mistake when assigning the J Contact Solid. I selected PART_NAME.SOLID_NAME.SHELL_NAME instead of just PART_NAME.SOLID_NAME, and those were the shells that were causing the tremendous slowdown in the model preparation. I fixed those definitions and the waiting period is gone! Back to normal. Another learning moment! Thanks very much for the help Greg!!

Shell Geometry is Very Large?

James Parkus — Thu, 18 Dec 2025 12:52:20 GMT

Hello,

I recently made some updates to my ACAR templates in which I added many clearance and new contact definitions (about 15 clearances, 15 contacts). The contact definitions are not really new, but I changed them a bit. Now when I try to Submit a General Actuation Analysis (Files Only) to prepare for a co-simulation, I get the following prompt ... "The shell geometry is very large (253437 connections); so, converting to Parasolid geometry may take a long time. Do you want to Continue?"

I'm confused because I didn't add any new geometry from the last time I did a "Files Only" analysis and that worked fine (and has been working for a few months without issue). Was it the new clearance and contact definitions? Could it be that some parts are not hidden so it's pulling in geometry that wasn't visible before? Not really sure of the cause for this significant computation time hit to my workflow.

Best, James

2021.0.1 Adams Car

RE: Shell Geometry is Very Large?

James Parkus — Thu, 18 Dec 2025 14:04:10 GMT

Understood, I can try to switch everything over to Parasolids. I've never worried too much about the difference of those two until now, but that's workable. Just to be clear, I am using 2021.0.1 so this may not be the case in newer Adams versions. Unfortunately, I am still unable to use newer versions of Adams for this specific effort.

I will attempt some clean-up and let you know how it goes.

RE: Shell Geometry is Very Large?

greg.wheeler — Thu, 18 Dec 2025 13:53:35 GMT

If it takes an hour just to prepare your model for Solver, then we have a performance bug that we can investigate.

Reducing the number of clearances won't help, unless that would also reduce the number of individual shell objects that need to be converted to Parasolid.

If it is possible for you to use Parasolid geometry in your template instead of shell geometry, that would avoid this geometry conversion step when you submit an analysis.

RE: Shell Geometry is Very Large?

James Parkus — Thu, 18 Dec 2025 13:48:16 GMT

Greg, thanks for the response. I figured it was the clearance requests, they seem pretty taxing overall. Do you think I could abridge this by computing clearances after the analysis in post-processing? It takes about 1hr for the "Files Only" analysis to complete the 253437 connections. I might try to reduce the number of clearances in this case to only what's absolutely necessary.

RE: Shell Geometry is Very Large?

greg.wheeler — Thu, 18 Dec 2025 13:44:28 GMT

Hi James. Yes, the change in behavior is due to the clearance/contact definitions. Normally, geometry isn't written to the adm file since Solver wouldn't care about it. But obviously Solver needs geometry in the case of clearance and contact. View converts your shell geometry into Parasolid for consumption by Solver. I'm curious how long this operation takes. I've seen cases where's it's unbearably slow. If that's your experience, let us know!

RE: modifying aevhybrid's in wheel motors wheights and gears

Alexis Del Rio — Mon, 01 Dec 2025 06:14:23 GMT

Can you tell me the constant radius cornering setting you ran so I can replicate?

modifying aevhybrid's in wheel motors wheights and gears

Yannic Wulfdeit — Tue, 25 Nov 2025 17:41:17 GMT

When I modify my in-wheel-motors motor diameters and weight, or gears to fit my actual vehicle my model stops passing static equilibrium