WS1: Inspection of monolithic samples detected defects up to 10 mm (IRT) and 15 mm (UT), while the sandwich samples revealed defects only in the front skin or disbonding between the skin and foam core. The results indicated that IRT is more effective for surface defects, while UT detects deeper flaws. According to the tests, the MPP would be capable of inspecting a carbody in 12 hours using IRT and 6 hours using UT. Despite the progress made in GEARBODIES, further work is required to detect defects through foam and to achieve a fully automated (hard- and software) inspection platform.
The LCC was estimated for two automation scenarios: the LCC was 14% lower with mid automation and 53 % with full automation. These savings are driven by reductions in inspection times, energy consumption and the time needed to review the results if automation is increased which outweigh the greater investment cost required for enhanced automation.
WS2.1: Carbon Nanotubes (CNTs) was incorporated into elastomeric formulations, resulting in significant enhancements in mechanical properties, such as tear and tensile strength, elongation at break, and hardness. These improvements suggest an increase lifetime of the elastomer components. However, the application of nanotechnology to reinforce the interface between elastomeric and metallic parts did not show improvements in adhesion strength. The fatigue tests for the prototypes demonstrated variations in stiffness, suggesting the need for further optimization of elastomeric formulations and the potential need of components redesign.
Based on an extension of the maintenance interval from every four to every five bogie overhauls the LCC of bushes was estimated to decrease by 24.3%. The fatigue tests for the conical springs suggested that the durability of the components had not increased. To inform future research on conical springs it was estimated that if the component could be replaced every other bogie overhaul rather than each time as they are at present then the LCC of the components would decrease by 44.1%.
WS2.2: Despite theoretical expectations from the bearing prototype, rig tests analysis didn't fully confirm the anticipated advantages. Therefore, further short-to-medium-term development is recommended, with a focus on the conventional tapered-roller layout. Research indicated potential incremental improvements through optimization of component geometry, including roller geometry, contact roller and ring, cage geometry, and surface tolerances of the rings. The results indicated that all tested HEAs generally outperformed the state-of-the-art steel used as a reference. Polyether-ether-ketone (PEEK) emerged as a promising candidate, being compared with the widely used glass-reinforced polyamide PA66. PEEK exhibited interesting properties, such as lower absorption from the surrounding environment and lower variations of key properties with aging.
The present value of LCC was estimated to decrease by 43% with the ‘focused concept’ bearing which is based on what is thought to be possible in the short medium term based on the testing done in the project. These savings are driven by the reduced frequency of interventions which means that fewer components need to be purchased and less labour and energy are required for the installation and reconditioning of the bearings.
