Innovative shock absorber for armoured vehicles


The SRB Project design phase (CDR) is reaching its completion. The project aims to develop a revolutionary hydropneumatic rotary suspension for armoured vehicles. This initiative, in the framework of the EDIDP (European Defence Industrial Development Programme) 2020 programme, is about to complete this crucial stage of the project.

After 22 months of intense collaborative work, the consortium formed by Piedrafita Systems, Repack-S and IB Fischer CFD + Engineering GmbH has almost completed the design of this innovative solution. Piedrafita Systems a leading Spanish company in technology for innovative mobility systems in land defence, ensure the coordination of all 3 companies.

Repack-S, a A French engineering company specialised in designing & manufacturing high performance sealing & self-lubricated bearing solutions have overcome several obstacles related to the sealing of this high-performance suspension. Finally, IB Fischer CFD + Engineering GmbH, a German company expert in CFD (Computational Fluid Dynamics), have used the simulation of fluid behaviour to validate the prototype design.

The imminent completion of the design phase marks an important milestone in the SRB Project. This achievement is due to the joint effort and dedication of the engineering teams of the three companies in the consortium, who are enthusiastic about the progress made so far and eager to move on to the next stage: prototyping and testing.

The design phase has been crucial to validate if the technical challenges presented by the performance brief can be overcome and to validate that the new revolutionary hydro pneumatic rotary damper can be retrofitted to a wide range of existing battle tanks without significant modifications.

Repack-S completed an extensive material characterization test program, and performed a large number of numerical simulations to determine the best sealing solutions for all the critical locations in the damper.

Indeed the various sealing solutions due to be used in this revolutionary damper will be subjected to extreme service conditions, such as high pressure, rapidly changing dynamic loads and a wide temperature range. They will also have to be chemically compatible with the damper oil.

The Repack-S engineering team has extensive experience in designing complex sealing & self-lubricated bearing systems that must meet specific performance targets without compromising on reliability. Advanced numerical tools are used to great effect by the Repack-S engineers to simulate the behaviour of new sealing solutions when subjected to various stress conditions. However results of numerical simulations must be based on the right physics laws, on real material characteristics as well as on properly defined boundary conditions to be meaningful. Therefore, Repack-S engineers had to complete an exhaustive material characterisation campaign to identify potentially suitable material candidates. Some of the material properties were obtained using conventional lab equipment whereas other characteristics required Repack-S to reconfigure some of their existing test benches.

IB Fischer CFD + Engineering GmbH is playing a key role in the project, using advanced fluid simulations to analyse and validate the behaviour of the suspension in various situations, including its interaction with other objects and fluids, different temperatures and speeds. This has allowed the generation of a design system that will support the creation of a robust and efficient prototype.

Piedrafita Systems brings to the Consortium its prior know-how in designing damping systems that have already been validated and are being used in several platform around the world.  The development of a test bench for special vehicle suspensions, carried out with the collaboration of the Spanish organisation CDTI (Centre for the Development of Industrial Technology), was pivotal in laying the foundations for this new innovative rotary damper.

A new purpose-built facility was recently inaugurated and presented to the relevant actors in the industry and the Spanish national defence field. The new test bench is the largest in Europe. It can replicate the loading of dampers as found on armored vehicles up to 70 Tonnes, such as the Leopard 2, the Leclerc battle tanks, or the future projects like E-MBT or MGCS. It can produce extreme dynamic load conditions and follow specific load profiles.

It is a key capacity within the consortium and shall enable the beneficiaries to perform the most advanced and demanding tests on the suspension system.

This bench will be where the complete test of the prototype created in this project will be carried out, validating the technology which will be developed.

Furthermore, the Repack-S internal laboratory was used extensively to validate the primary sealing concerns, such as large deformations under pressure, wear prediction, oil compatibility and material characterization.

Christophe Rodriguez, CEO of Repack-S said: “We at Repack-S are honoured to be able to contribute to the SRB Project within this consortium. We believe in our capability to overcome the most complex challenges with our strong engineering expertise”.

As the Technical Director of Piedrafita, Luis Barrada, said during the inauguration of the test bench: “The SRB project so far has shown that the sealing system is reliable; that the hydro-pneumatic system is reliable.”

The conclusion of the design phase is a significant step towards the ultimate goal of the SRB Project: to provide a state-of-the-art complete rotary hydropneumatic suspension solution for tracked armoured vehicles. This technology will improve mobility, eliminate the torsion bar, increase suspension travel and offer a progressive spring characteristic, providing unparalleled performance in service.

Photos courtesy Piedrafita SystemsMain photo credit: Plakboeka on Visualhunt