One of the most important task in the design process is the assessment of cyclic loading since half of the mechanical failures are due to fatigue. A robust and reliable fatigue assessment requires a well understanding of fatigue mechanisms of structural materials. The conventional approach used in the past relied on the infinite life duration with the assumption that stress values below the conventional fatigue limit would not produce any failure. Recent study have shown that under Very High Cycle Fatigue (VHCF) the failure can happen beyond 107 cycles even if the load is below the fatigue limit. In order to guarantee the long-term safety of mechanical components, the VHCF fracture mechanisms need to be fully described. Below 107 cycles the damage would start on the surface as invisible microcracks in slip bands. The deformation would be accumulated and become a visible crack. In order to improve the fatigue strength of metallic part or members, a layer of compressive residual stress is produced on the external surface to postpone the crack nucleation and propagation. For VHCF the damage would start as subsurface crack nucleating from internal metallurgical discontinuities and the fracture process is characterised by the fisheye morphology with a central area called fine granular area (FGA). This project will look at the mechanisms of the nucleation and propagation of the internal crack in the VHCF of aluminium alloy for railway application to specifically investigate the effects of the residual stresses and biaxial stress field. The work will be carried out implementing FE models to investigate the stress field and the residual stresses and performing tests at VHCF. The candidate will be also involved in the development of an “ad hoc” testing equipment to produce data at high frequency. The work will be in collaboration with Universities in the UK and in Europe.