Meccanica Magazine n. 4

ENG
NextGear – Providing concepts and demonstrators for the next
generation of robust and sustainable running gear
NextGear - NEXT generation methods, concepts and solutions for
the design of robust and sustainable running GEAR was concluded
in 2022 with success, providing several innovative solutions for the
railways industry. The project started in late 2019 with 14 partners
coming from academia, component manufacturers and end-users
of the railway sector. The partners worked on several aspects of the
running gear from a global cost model, to smart actuating systems
and new materials for producing components for the running gear.
DMEC have worked extensively on the different aspects of the project
contributing to the realization of some of the main results of the
project. In particular, DMEC researchers have contributed by studying
novel additive manufacturing solution for spare parts and the use of
composite materials as lightweight solutions in the running gear.
Metal additive manufacturing can have a positive impact on the
logistics of spare and repair parts for railways. In NEXTGEAR
DMEC researchers redesigned and manufactured a prototype
ATP antenna bracket for the Madrid subway trains using additive
manufacturing (AM). The component was topologically optimized by
DMEC researchers using acceleration data gathered on the actual
trains, improving the safety factor while reducing the total weight
by 60%. The new design was produced by laser powder bed fusion
(LPBF) incorporating 18 parts to only two and post-processed using
a tailored heat treatment. The total production time was less than 2
weeks, which shows the potential of metal AM for reducsg the use
of resources and improving performances in the railway industry. On
11th January 2022 the new antenna bracket was tested on a Metro the
Madrid vehicle running on the test track and performed well.
One main objective in the design of modern railway vehicles is
mass reduction and the reduction of the damage generated to the
infrastructure. In this regard, reducing the mass of the wheelsets
is of paramount importance as the un-sprung masses are directly
in contact with the track and hence are responsible for increased
stresses in the rails and in other track components. The “wheelset of
the future” workpackage, led by DMEC, aimed at defining a technology
concept and a complete set of functional specifications for a wheelset
with a hybrid metallic composite (HMC) axle. The solution researched
in the project is an axle for an inboard bearing trailer wheelset for use
in metro vehicles. The HMC (Hybrid Metallic-Composite) axle concept
was investigated in respect of a number of interrelated technical
issues, including the structural design and the optimization of fibre
layup, the design of composite-to-metallic adhesive joints to provide
suitable interfaces to the wheels, the identification of techniques
for non-destructive testing and structural health monitoring of the
HMC axle, the effect of impact with ballast stones, the manufacturing
methods, with a focus on the optimization of the pattern for filament
winding of fibres, the vibro-acoustics of the wheelset with HMC axle.
Within the project several other exciting concepts were investigated
and demonstrated, including a frame for a two-axle vehicle made of
carbon fiber reinforced polymeric composite material, and an active
vibration control system with a dedicated actuator. After conclusion
of the project, several relevant impacts of the project continue to
emerge as some of the demonstrated technologies are included in
the Shift2Rail Catalogue of Solutions and showcased in InnoTrans
2022 trade fair for rail transport technology, which was held in Berlin,
in September 2022.
meccanica magazine
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