Development of a High Performance Torsion Bar Spring

As the need for higher speed, greater load carrying capacity transport vehicles increases,
particularly in the truck & rail vehicle markets, demands on conventional suspension systems
increases. At the same time vehicle manufacturers & operators wish to maintain existing
vehicle suspension designs (space envelope considerations) & operating parameters (ground
clearance, stiffness, service life).
To enable operation of torsion & stabiliser bars at higher dynamic loads without reduction in
service life, this project aims to develop a manufacturing process to explore novel
strengthening & toughening techniques of a new steel grade, to target an ultrahigh
ultimate tensile strength (UTS) along with sufficient toughness,
fatigue strength etc. for a heavy duty torsion bar suspension spring. It is envisaged that
applications could
be developed realising weight & fuel savings.
Due to the level of hardness of the steel, there are significant technical challenges posed
in the manufacture of the suspension elements. This in turn has a commercial impact as target
markets are highly price sensitive & competitive. The objective of this project is to address
these technical challenges to produce a commercially viable solution.
Novel structural strengthening & toughening techniques for ultra-high strength steels will be
assessed by Sheffield Hallam University (SHU) & a novel heat treatment route will be
developed to facilitate the manufacturing of ultra-high-strength components.
Delivery of this project will provide Tinsley Bridge (TB) with a unique manufacturing
capability & product that will support the UK. There is an immediate opportunity to retain in
the UK major defence related contracts if the project can be
completely promptly & the longer term global opportunity in multiple vehicle & rail markets.