Overview:
As an engineer in the UTV and ATV industry, you're tasked with designing robust, high-performance vehicles capable of thriving in the most demanding off-road conditions. From optimizing suspension geometry and frame integrity to balancing weight, improving ride comfort, and meeting regulatory requirements, every design decision directly impacts vehicle performance and reliability. And with the high costs of physical testing, getting it right the first time is more critical than ever.
Altair MotionSolve, a powerful multibody dynamics (MBD) simulation tool, gives you the ability to simulate complete vehicle systems in a highly detailed, physics-based virtual environment. With its comprehensive vehicle library and advanced modeling capabilities, MotionSolve allows you to evaluate full 3D kinematics, compliance, and internal load paths under real-world operating conditions — including dynamic terrain interactions.
MotionSolve’s soft soil modeling capabilities provide crucial insights into how tires interact with deformable terrain. This is particularly important when tuning suspension and drivetrain systems for performance across varied surfaces like sand or mud. The simulation outputs are grounded in terramechanics theory and offer quantitative data to guide design decisions:
- Plastic Sinkage: Measures permanent soil deformation from tire loading, indicating how much the soil is compressed beyond recovery.
- Longitudinal Resistance: Captures the portion of the tire’s forward resistance caused by soil normal stress.
- Longitudinal Shear: Represents the contribution of soil shear stress to the forward force on the tire — critical for traction analysis.
- Lateral Bulldozing Force: Quantifies the resistance generated by soil displaced laterally as the tire turns or slides sideways.
- Lateral Shear Force: Calculates the side force resulting from soil shear stress, which directly impacts vehicle handling and stability.
- Tire Sinkage: Measures the compressive deformation of soil at the tire's contact patch — essential for predicting ride height and ground clearance changes.
These outputs allow you to understand and optimize tire-soil interactions under various load and terrain conditions — reducing field testing time and improving early design decisions.
Looking ahead, engineers requiring even more detailed terrain-vehicle interaction can leverage Altair EDEM, a discrete element modeling (DEM) tool that works alongside MotionSolve. EDEM enables granular-level simulation of soil behavior, making it ideal for advanced R&D work where detailed insight into particle-material interactions is required.
We have created an additional vehicle library that resembles a decent number of ATV and UTV vehicles on the market.
For the Front Suspension we offer MacPherson and SLA.
Figure 1: Front Suspension
For the rear we offer MacPherson, SLA, H-Arm, Multi Link with Trailing Arm and Trailing arm.
Figure 2: Rear Suspension
For the Full vehicle model, we now have a Rear Mounted Engine.
Figure 3: Full Vehicle Assembly
This library utilizes the events dedicated to the Car & Truck Library.
Figure 4: Event Library
Figure 5: Ride Analysis of Multi Link with Trailing Arm
Figure 6: Double Lane Change
Prerequisite:
SOFTWARE REQUIREMENTS:
- Operating System: Windows
- MotionView (2025 or newer)
- MotionSolve (2025 or newer)
- Workable knowledge of MotionView and Vehicle Modeling preferred.
Usage/Installation Instructions:
Library Definition
ATV_UTV.zip [Click Here]
Post-Requisite:
Modeling Steps:
- Enable vehicle tools in extensions. File -> Extensions -> Vehicle Tools.
- In the Vehicle Tools menu, select Libraries.
- Alter the Wizard Library to “User/Custom library”.
- Update each input to refer to the ATV_UTV folder.
- Assembly Wizard file: “<directory>/ ATV_UTV /model_wizard.wzd”.
- Task Wizard File: “<directory>/ ATV_UTV /task_wizard.wzd”.
- MDL standard include file: “<directory>/ ATV_UTV / std_inc.mdl”.
- Wizard library directory: “<directory>/ ATV_UTV”.
- Report log file: Default.
- Utilize the Assembly Wizard to construct your vehicle model.
- Update the suspension model to prototype specifics.
- Analyze and verify the Half Car and Full vehicle model with event s in the Entity Browser.
- Update event to desired run parameters.
- Run model and extract results.
Results
Each vehicle can undergo a comprehensive range of evaluation tests, from half-car simulations to full-vehicle assessments. Detailed reports are accessible through the "Analyze" or "Vehicle Tools" menus. Additionally, further results can be visualized and plotted using HyperGraph for detailed analysis.
Figure 7: Steer and Drive Torque
Figure 8: Longitudinal Acceleration and Velocity
Figure 9: Tire Vertical Force
Figure 10: Tire Longitudinal Force
Figure 11: Tire Longitudinal Slip
Figure 12: Suspension Travel
CONCLUSION
In the highly competitive and demanding UTV and ATV market, the ability to design, simulate, and validate off-road vehicle performance early in the development process is critical. Altair MotionSolve, with its physics-based multibody dynamics simulation capabilities and soft soil modeling, equips engineers with the tools to accurately predict vehicle behavior under real-world conditions. By simulating dynamic terrain interactions and providing deep insight into tire-soil mechanics, MotionSolve significantly reduces the need for costly physical testing while improving design quality and decision-making.
Additional Resources
