REFRESCO begins by benchmarking the most promising new materials (and associated certification processes) being used within and outside of the transport sector, which could be implemented in railway rolling stock. It also carries out an analysis of the gaps in the current framework which will need to be filled to allow the implementation of new materials. This will be accompanied by the identification of requirements certification processes. This work (which is carried out in Work Package 2) will review the materials and associated certification procedures currently used in rail and other sectors (such as aeronautics, marine, energy and automotive), identify shortcomings and gaps in approval methodologies for new materials in the rail sector and set out the requirements for certification processes and standards, ensuring the safety of rail carbody structures is at least maintained by the introduction of any future new structural materials. The results of this WP will then be used as inputs by the WPs below:
- WP3: This Work Package will identify those materials which meet the applicable fire and smoke requirements. It shall also propose the optimum design implementation of these materials, such that the requirements stated in the standard can be met. It will also examine the implications for noise and vibration of using composites, in comparison with metallic structures. The specificity of composite material properties, modelling and experimental techniques used for characterising composite materials in comparison with metallic structures will be summarised. The impact of the introduction of composites and other lightweight materials on electrical and Electromagnetic Compatibility performance will also be evaluated;
- WP4: This Work Package will fill the gaps concerning the structural requirements of railway vehicle carbodies, including for example fatigue, for the use of high performance composite materials instead of metallic ones, by generating the needed know-how to understand which changes in standards might be necessary. This will include material characterisation and modelling procedures; calculation methodologies and failure criteria; damage influence (for example ballast impacts); and static and fatigue testing procedures;
- WP5: The objective of this Work Package is to provide the tools and processes to certify carbody structures built from new materials (hybrid or entirely) from the point of view of crashworthiness requirements. As is already known, rolling stock carbodies are currently made primarily of steel or aluminium. Vehicles using new materials shall require a certification process to provide an equivalent level of confidence to that which the sector currently has in metallic structures. Work on energy absorption and crash performance simulations will go towards the recommendations for the certification process which are expected from this Work Package;
- WP6: While there are detailed and accepted methods and processes for validation and certification of welded metal structures in the rail industry, regulations for joining technologies in connection with new materials are currently not available. This Work Package aims to develop the needed quality criteria and validation methods for manufacturing and joining of structural elements from composite and sandwich materials or hybrid structures. Aspects of particular importance will be materials manufacturing and processes and joint behaviour and acceptance criteria;
- WP7: This part of the project addresses strategies for managing various kinds of defects that can occur in the life of a carbody, with special focus on the implications of possible new materials. This Work Package will review current practices and requirements for the inspection of carbody structures within the rail sector, before investigating damage tolerance strategies in other industries where composites are used, and health monitoring and non-destructive inspection, also from outside of the rail sector. This work will finish with recommendations for how such techniques and processes can be implemented for new materials in the rail sector;
- WP8: This Work Package focuses on repair and maintenance of carbody structures built from new materials. It considers the various types of damage which can occur to composite structures, as well as how such damage can be identified and evaluated. This work includes proposing repair criteria and evaluating repair technologies, as well as the creation of a maintenance strategy, and will take advantage of learning gained within other sectors having already implemented composites and other lightweight materials.
These Work Packages are accompanied by WP (Work Package 9) dedicated to the dissemination of the project work and its conclusions. This Work Package will gather the proposals for modifications in the standardisation and regulatory context to allow the introduction of new structural materials in railway rolling stock, and will present them to the different actors in the rail sector.