Parametric sizing study for the design of a lightweight composite railway axle

The potential for lightweighting of railway axles was investigated to primarily reduce the unsprung mass of a rail vehicle. The reduction of unsprung mass equates to an overall lighter train which will help to reduce track damage, energy consumption and total operating costs. This work was performed within the NEXTGEAR project which is ascribed under the Shift2Rail program. This paper focusses on the design of a composite railway axle as part of the "Wheelset of the future" Work Package 3. A parametric study is presented for the sizing of one of the design concepts (the full-length pre-manufactured tube axle) that shows the greatest potential for mass reduction. This study uses the existing hollow steel axle as a benchmark for mass, strength and stiffness. The estimated mass of this composite axle is 50 kg. This represents an estimated mass reduction of 75% compared to the existing hollow steel axle.