Making exceptional vehicles with Hexagon: CAE solutions for multibody dynamics and nonlinear analysis
Melinda Corley – Product Marketing Manager Multiphysics, Hexagon’s Manufacturing Intelligence division
Making safe, comfortable, and rugged vehicles
TATRA uses Hexagon CAE solutions for multibody dynamics and nonlinear analysis to make exceptional vehicles.
TATRA’S mission is to create vehicles that are safe, comfortable, cost-effective, and efficient to manufacture. This can be an ambitious goal, as these factors are deeply interconnected. Safety and comfort must be balanced with cost constraints, all while considering the feasibility of production. Decisions in one area can significantly impact the others, which makes the ability to understand how disparate systems within a vehicle interact critical to producing a safe, reliable, and efficient truck.
The road to reducing prototypes
Unfortunately, creating physical prototypes to test each variable in accurate operating conditions is cost and time-prohibitive. Simulating these interactions with CAE (Computer-Aided Engineering) software can offer companies like TATRA an accurate and reliable way to optimise systems and components and validate them for safety, comfort and manufacturability.TATRA, a company with a rich heritage spanning more than 170 years, has played a pivotal role in shaping the automotive industry both in the Czech Republic and around the world. With its subsidiary, TATRA METALURGIE a.s., the company focuses on producing heavy-duty off-road vehicles and trucks for combined on/off-road transport and continually enhances its offerings to meet the ever-evolving demands of its customers. TATRA-branded trucks are renowned for their exceptional go-anywhere ability in challenging terrains and extreme weather conditions, high reliability, and outstanding utility properties, making them ideal for extreme conditions like frosty weather and scorching desert temperatures.
Figure 1. 4x4 fire truck chassis-cab from TATRA
Creating trucks that satisfy customers and regulations
In the automotive industry, creating engineering solutions that meet regulatory requirements is critical for success. For satisfactory vehicle performance, some requirements must be met for braking, steering, acceleration, and more. To fulfil these obligations, TATRA relies on Hexagon CAE solutions to ensure their vehicles meet industry andgovernment regulations without prototypes. For example, lifting and tie-down elements at emergency vehicle frames have specific requirements called STANAG standards in the defence sector, Homologation regulations for RUPD (rear underrun protective device) and FOPS/ROPS (FallingObject protective / Roll-over Protective Structures) mean meeting passive safety requirements for civilian and industrial cargo transport.
These standards and regulations extend to performance at high speeds over difficult terrain or in heavy off-road conditions, driving comfort, vehicle stability on turns and on slopes, and high chassis rigidity. Ensuring regulatory compliance and meeting standards requires accurate simulation capabilities to evaluate design concepts, perform trade-off studies, and improve vehicle performance.
To optimise designs to meet these regulations and high standards, TATRA uses Adams from Hexagon to perform multibody dynamics simulations and Marc for nonlinear analysis to correlate simulation results with physical test data for extremely accurate and reliable predictions.
The simulations performed with Adams allow TATRA to validate full vehicle models against physical test data so the company can predict vehicle performance using different driving manoeuvres and set tyre parameters. Other capabilities in Adams ensure that TATRA meets regulatory requirements and industry standards for braking systems and suspension systems. Adams enables the company to predict braking distances for loaded and empty trucks and the virtual hydraulic testing rig in Adams allows TATRA to design vehicles with appropriate stiffness and damping settings for better comfort, as well as determine the fatigue life of the cabin suspension system.
Figure 2. Braking simulations are used to validate that trucks will meet requirements and homologation for empty and loaded vehicles.
Powerful solutions for multibody dynamics and nonlinear analysis
Hexagon CAE solutions help TATRA meet regulations and optimise the truck designs to achieve better performance. Adams plays a crucial role in highlighting the capabilities of vehicle design and opportunities for optimisation.TATRA uses Adams to make informed decisions on powertrain and cabin mount locations and their orientations and manage the transition of forces from the mainframe to the cabin. Adams simulations help the company determine the optimised load distribution on the axles and account for changes to the wheelbase or a shift in the centre of gravity for the components. Studying these factors results in reduced cabin vibrations, lower steering effort, better comfort, lighter components, and lower manufacturing costs. These simulations also provide critical road load data inputs for FEM (Finite Element Model) calculations, where the company uses MSC Apex as a pre-processor for shell mesh object generation.
The interoperability of Hexagon’s solutions is key to Tatra’s design and engineering processes. The integration of MSC Apex with Adams streamlines the process of preparing mesh and interface points for flexible bodies, such as frames and axles. This integrated solution facilitates the creation of MNF files for flexible bodies, making the design process more efficient and accurate.
Marc is used to establish connections with Simufact Forming for external loading. This enables it to analyse the impact of external loads on its products, enhancing overall product design and performance. These integrated workflows save valuable engineering time, making it easier to adapt to rapidly changing market conditions and new requirements.
Simufact Forming empowers TATRA to simulate the technological processes of truck part manufacturing, including welding and forming. These simulations allow the company to understand the impact of manufacturing on its designs, enhancing product quality and efficiency. It can also integrate these results as pre-stress data with operational load sets, providing a more comprehensive view of vehicle performance.
Figure 3. The full-vehicle model results are correlated with physical tests.
Figure 4. Simulations in Adams help TATRA choose ideal mounting conditions and balance price, comfort, and durability inputs for FEM calculation.
Figure 5. TATRA uses Adams to simulate vibrations for critical revolutions and torque and forces against the frame, and uses the results to inform FEM.
Figure 6. Marc/Mentat is used to establish connections with Simufact forming.
Optimised designs and virtual testing mean better, more cost-efficient vehicles
The Hexagon software multibody dynamics (MBD) solution, validated by experimental tests and in collaboration with technical universities, has significantly improved TATRA’s design process. The company can rely on these simulations to make informed decisions and optimise their designs, ensuring vehicles that meet safety, comfort, cost, and manufacturability requirements.
The collaboration between TATRA and Hexagon has allowed he company to meet their complex challenges of creating safe, comfortable, cost-effective, and easy-to-manufacture vehicles. Using the power of advanced simulation and CAE tools, it has not only met industry and government regulations but has also optimised designs to excel in a competitive automotive market. With an eye on the future, TATRA is poised to continue innovating and delivering exceptional vehicles to its customers.
Figure 7. Marc integrates with Simufact Forming for external loading analysis.