Suspensions for off-road vehicles with extreme performance

For a manufacturer of off-road vehicles with extreme performance, we worked with the Engineering Company in charge of the vehicle development in order to design not only the suspension system with rigid axle, but also the steering system.
In the suspension with rigid axle, the tyres on the same axe are rigidly connected by a bar with load-bearing function.
It is a very solid and reliable system, perfect for transportation of high loads. This system is the main aspect of real off-road vehicles, those ones with most extreme performance in order to win the most difficult off-road adventures.
FRAP challenge was to design a suspension system with strut stabilizers that could bear high buckling in spite of high conical angles that were necessary for the axle design.
High buckling are actually not so compatible with conical angles. This is why we worked carefully on the materials to be employed, as well as on their performance: in particular way, mechanical characteristics of the materials, and the moment of inertia of the section of the strut stabilizer were the real protagonists of this project.
The Finite Element Analysis, made with computer simulation of the behaviour of the strut stabilizers under maximum load, as well as with fatigue cycle simulation, allowed us to validate the project phase for materials and design.
Then, the test bench validated the whole project, confirming the respect of all parameters related to the life of each component, and to the life cycle of the final product itself.
The design of the steering system was a another, interesting challenge: it was necessary to attentively calculate the stiffness of the steering bar to protect the steering box in case of impact. The customer specifically required FRAP to consider all events the vehicle could be involved in, giving maximum priority to the protection of the most complex elements, and requiring deformation of the ones that could be replaced more easily. This vehicle must be repaired and maintained in any lost corner of the world: the design of its components must take it into account.
Our Engineering Department had to carefully balance all aspects of the stiffness of the steering system in case of impact: not too high, in order not to damage the steering box, but not too elastic either, in order to comply with the severe safety requirements.
FEM analysis played an important support role during the project phase, and test bench finally validated our solution.
The customer got what he needed, absolutely on time and respecting all safety standards: all essential aspects for a vehicle that will have to face the most thrilling adventures worldwide.