Adams Car - Recent Threads

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

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

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

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!

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

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

How can I find the wheelbase of the default cars?

Nader Karballaeezadeh — Sat, 22 Nov 2025 11:18:48 GMT

Hi, everyone.

I am working on ADAMS/car 2024.2. I selected to use the predefined cars, here SEDAN FWD, for my analysis. I require to know the value of wheelbase for this car. Could you please guide me on how and from which parts of the soft I can find it?

Toe/Camber Issues with Trailing Arm Suspension

Logan Laing — Sun, 26 Oct 2025 20:08:14 GMT

Hello,

I am on a Baja SAE college team and am attempting to model the suspension for this year's vehicle in ADAMS Car. The plan is to use a trailing arm for rear suspension. I have attached the template file that I modeled. My problem is with the toe/camber for the wheel hub or wheel. When the 'Parallel Wheel Travel' Suspension Analysis is ran using the _MDI_SUSPENSION_TESTRIG, the toe/camber for the tire does match the appropriate motion of the trailing arm. The hub or tire delays the camber and toe change from the trailing arm motion, which would not happen with the real-life trailing arm as the hub is not allowed to pivot on the trailing arm.

I want the wheel/hub to be oriented with the plane made from the hardpoints UPTTAS, LTRTAS, and either UOAP or LOAP using the YX axis. What should I do to properly setup the toe/camber so that when the analysis is ran, the toe/camber is accurate to the model and can be used for design changes and updates?

nexus.hexagon.com/.../_5F00_Rear_5F00_Suspension_5F00_Trailing_5F00_Arm.zip

Defining Gravity for New Templates in ACAR

James Parkus — Thu, 23 Oct 2025 10:07:09 GMT

Hey folks,

I am trying to understand the finer details of how Adams/Car defines gravity when creating a new template, sub-assembly, and an assembly part. The model I'm working is not Earth Gravity and I've setup an "acarAS.cmd" command file to modify the already-created gravity vector.

This leads me to two questions;

When and where does ACAR create the gravity vector and can I adjust the value there so I don't need to worry about using the "acarAS.cmd" file?
If there are gravity vectors in templates set to Earth gravity, and then those same templates used in an assembly (via sub-assemblies) which has a gravity vector set to a non-Earth gravity (say Mars for example) – which gravity will be used in the simulation of the assembly?

Best,

James

Code for acarAS.cmd file

if cond=((eval(.system_defaults.units_consistency_factor )) == 0.)
default units length=meter mass=kg force=newton time=Second angle=degrees frequency=hz
view manage modify spacing_for_grid=1.0
end


color mod color=.colors.background red_component= 0.16 &
green_component=0.46 &
blue_component= 0.65 &
gradient= "none"


force modify body gravitational gravity = .__ACAR.gravity &
x_comp = 0.0 &
y_comp = 0.0 &
z_comp = (1.35(m/s/s))

normal modes for the leaf spring assembly

TR202609017719 — Wed, 22 Oct 2025 15:59:20 GMT

I tried performing the normal modes analysis of leaf spring model with 9 leaf's in Adams using vibration plugin with operating point in static and assembly state. Both of them are taking forever to run.
Is it really possible to extract natural frequencies of the leaf spring assembly?

Looking for the Adams Car Command Guide

Timothy Lynch — Mon, 13 Oct 2025 06:42:25 GMT

Is there an Adams Car Command Guide?

I'm looking from something similar to the one for Adams View located here:

nexus.hexagon.com/.../Adams_2024.1_Adams_View_Command_User_Guide.pdf

I found this on the documentation site but searching for command, but it only lists Command Guides for Adams View for each version.

https://nexus.hexagon.com/documentationcenter/en-US/bundle?cluster=true&exclude_metadata_filter.field=display-type&exclude_metadata_filter.value=inline&labelkey=prod-adams&q=command&rpp=10&sort.field=last_uploaded&sort.value=desc&fromSlug=adams

I'm going through an existing command file which includes acar and amech commands (so I have the same question for amech, but I understand this is a Car forum), and I'd like to review the command guide to understand all the options / arguments.

Thanks!

--Tim

Roadtrain Modeling in Adams/Car

Hugo Cavalini Agudelo — Mon, 01 Sep 2025 03:14:41 GMT

Hello colleagues,

I am currently developing a sugarcane roadtrain model (as shown below) as part of my master's thesis in Adams/Car.

At this stage, I am working on modeling the dolly. My approach has been to use msc_truck_rigid_tractor as a base, since it already includes a fifth wheel, but so far I have not been successful with this approach.
I would appreciate any guidance from those who have experience with this type of vehicle modeling. In particular, I would like to know whether there are available examples of configurations involving a truck with both a trailer and a semi-trailer.

Thank you in advance for your support.

Moments in Contacts

sb.idiada — Tue, 12 Aug 2025 03:08:22 GMT

When contact is modeled in ADAMS, it creates forces as well as moments. Most of the time the moments values are quite random and difficult to comprehend. Also I am not able to imagine how a system with no rotational constrain can have moments. I want to know authenticity of the moment values, how they are calculated and whether to use them while addressing contact loads.

Running Forced Vibration analysis in ACAR about "Assembly" operating point

SCJoshi — Tue, 22 Jul 2025 12:14:32 GMT

ADAMS Vibration simulation through ADAMS View allows forced vibration about operating point set as "Assembly". However, in ADAMS Car only option available for Forced Vibration analysis is via "Script". How to perform an ADAMS Vibration simulation in ADAMS Car to match ADAMS View results.

Is there a script available which is equivalent to "Assembly" operating point?

Adams Car understeer gradient

shriharshaprasad.s — Sun, 15 Jun 2025 23:44:26 GMT

I was trying to plot understeer gradient curve of MDI default vehicle-(Steering wheel angle Vs lat acc)-what I observed is that there is peak at around 3300 mm/s^2 of lat acc. Apparently, this peak is coming in all the vehicle models including subcompact default vehicle. The same is reflecting in the model which we have built ourselves. Ran the entire model in kinematic mode but the peak still appears at that point, we have used default powertrain model and figuring out problem around it. I was wondering if anyone else has noticed this issue and how to tackle it. Is it an inherit error or something with model/test or solver setting?

Longitude Tire Force: low-mu to high-mu road

jsph_inc — Thu, 15 May 2025 13:56:36 GMT

Hi Everyone.

I am a bit stuck.

I am running a straight line ADAMS/Car full vehicle model. The vehicle is travelling on low-mu=0.1 and then enters high-mu=0.9. I am tracking the longitude tire force. While on the low-mu the tires are slipping.

I run two load cases (LC#1 , LC#2). LC#2 is the same as LC#1 except the vehicle enters the high-mu with a higher vehicle speed, higher wheel speed and more tire slip. Roughly same tire normal force.

The results predict that the longitude tire force magnitude is roughly the same between LC#1 and LC#2 shortly after entering the high-mu road. I would expect that LC#2 would have a larger tire longitudinal force since it enters the high-mu road with a higher vehicle speed, higher wheel speed and higher wheel slip.

I also reran using PAC89 and see the same trend.

Would the ADAMS/Tire be able to differentiate these two situations and generate larger longitudinal force if the vehicle hits a high-mu road with greater speed...what am I missing?

joe.

I am getting an error "step size too small", when running a quasi-static simulation (Default steering), Whereas when I run it with dynamic simulation(steering input) - the model works fine. What could be the reason for this? Any suggestions

shriharshaprasad.s — Mon, 12 May 2025 23:26:27 GMT

In Steering default test, the steering model created throws error indicating "Step size too small". But it works fine in dynamic simulation. What is the reason behind it?

GSE export from Matlab Simulink as .dll file.

Alfonso Campos Vazquez — Tue, 25 Mar 2025 21:14:17 GMT

Hello evryone, I'm trying to recreate the GSE Damper article to my vehicle prototype model on ADAMS CAR. While building the library or .dll file I have some trouble. First Simulink show me the following info:

Then, when first I try to replace the normal damper to a GSE damper, appears this message:

Next, while loading the .dll file, it doesn't export with the simulink file name, only as tbb.dll.

Also, when I load the .dll file the following window is shown:

Does anyone knows what to do?

Thank you.

VFC.read_xml

e-ondrej.petergac — Tue, 11 Mar 2025 04:16:22 GMT

Hello,

I am using the VFC_read_xml to read bushing splines in python:

from mdi.afc import vfc

xml = vfc.read_xml("mdi_0001_bus.xml")

# To get the stiffness

xml.child(type=vfc.ConnectorBushingProperties).x().stiffness().linear_data().rate()

# To get the spline values

xml.child(type=vfc.ConnectorBushingProperties).x().stiffness().spline_data().x_data()

xml.child(type=vfc.ConnectorBushingProperties).x().stiffness().spline_data().y_data()

I loop over all bushing files in assembly and use the spline data for calculation of the stiffness for each bushing.

The problem is that with this method the stiffness values evaluated from first xml file are used in all xml files and in values evaluated from first bus file after the processing of the XML file:

I asume that if I clear the xml at the and of the python function, then the problem will be solved.

I have tried

xml = None

but unfortunately it has not worked and there is no documentation for VFC - only the compiled vfc_xml.pyc can be found in ADAMS installation.

Does anybody has an idea if there is VFC function to clear the xml or how to empy xml?

Thanks,

Ondrej

You can find the original feed :How to read values from XML file?

ADAMS CAR Road Builder don't appear.

Alfonso Campos Vazquez — Fri, 07 Mar 2025 12:48:08 GMT

Hello everyone. I want to create a road using the road builder, but I have a trouible. Looking for that function it doesn't appear on the full vehicle analysis.Does anyone knows what to do? The ADAMS version is the 2024.2. I add a screenshot from the trouble:

How the brake torque is computed in brake_system_4Wdisk

jozef.bucha — Mon, 03 Feb 2025 07:02:22 GMT

Hello how is the Point-Torque computed in template brake_system_4Wdisk in acarshared database?

i.e. Point torque for left front actuator is defined:

2.0*pvs_front_piston_area

*IF(pvs_brake_reduction:0,pvs_front_brake_left_side_bias,left_reduction)

*pvs_front_brake_bias

*VARVAL(cis_brake_demand_adams_id)

*demand_to_authority_scale

*force_to_pressure_cnvt

*pvs_front_brake_mu

*pvs_front_effective_piston_radius

*STEP(VARVAL(left_front_wheel_omega),-velocity_step_threshold,1,velocity_step_threshold,-1)

with units involved according parameter variables and variables:

2.0*pvs_front_piston_area [mm2]

*IF(pvs_brake_reduction:0,pvs_front_brake_left_side_bias,left_reduction) [-]

*pvs_front_brake_bias [-]

*VARVAL(cis_brake_demand_adams_id) [%]

*demand_to_authority_scale [-]

*force_to_pressure_cnvt [-]1/mm2

*pvs_front_brake_mu [-]

*pvs_front_effective_piston_radius [mm]

*STEP(VARVAL(left_front_wheel_omega),-velocity_step_threshold,1,velocity_step_threshold,-1)

force_to_pressure_cnvt is defined as unitless, but force_to_pressure_cnvt=(0.1(1/mm**2))

Adams Car Help says:

As far as I know brake demand is used as percentage value, not force.

also in help is written:

but in template pvs_max_brake_value is defined as Force

Thanks for reply

Jozef

Initialize with previous results

GJJP — Wed, 04 Dec 2024 09:43:53 GMT

Hello, is it possible to initialize a model/simulation with the final results of a previous run?

This would be especially helpful for traversing different obstacles after the same equilibration phase, or for changing simulation time step after equilibration if an FMU is used.

Hi, I would like to create five link non-steerable suspension for the rear axle. I'm not sure how to deactivate/switch tie rod to trailing arm. Could anyone please help me how to do this? Thanks in advance!

HJ Yoo — Mon, 08 Jul 2024 12:36:18 GMT

Hi,
I would like to create five link non-steerable suspension for the rear axle. I'm not sure how to deactivate/switch tie rod to trailing arm. Could anyone please help me how to do this?
Thanks in advance!

Value of vas_steering demand using different integrator/formulation

jozef.bucha — Tue, 23 Apr 2024 08:24:43 GMT

Hello everybody

Can anybody tell me difference of vas_steering_demand value in postprocessor with different solver settings (Gstiff/I3, Gstiff/SI2, HHT/I3)

All simulations are done as DLC with speed 50 km/h with (MDI_Demo_Vehicle)

Results are pretty same (i.e. lateral disp, steering wheel has same angle)

Steering demand during DLC using gstiff_i3

Steering demand during DLC using hht_i3 or gstiff_si2

I do not understand value of steering demand, why is so much different while using hht or si2?

Thanks

Jozef