Impact of foreign object damage on the leading edge of TC11 titanium alloy aeroengine blade like specimen

Foreign object damage (FOD) generally occurs when hard body particles are ingested into an aero-engine fan and compressor blade when the engine is taxing, flying, or moving on the runway with definite speed. Ingested foreign object debris induces severe structural damage on the leading edge of the aero-engine blade due to the time-dependent axial fatigue loading under service conditions. Induced residual stresses due to foreign object damage play a major role in mitigating the rate of fatigue crack initiation and propagation, resulting in failure of components. In this present investigation, an explicit module of commercial software package LS-DYNA was used to simulate the impact of the GCr15 stainless steel ball (52,100 steel equivalent) against leading-edge specimen (TC11 titanium alloy) by varying speeds like the in-service operating speeds. A comparative study was carried out among obtained deformed geometry (Crater) and its dimensions from the numerical simulation with experimentation results. Variation of residual stresses in three mutually perpendicular directions along with depth has been determined to predict the possible location of crack initiation at different projectile impact velocities. A stress concentration factor has also been calculated at the vicinity of the impact, which is very much an essential factor for the fatigue strength evaluation of TC11 titanium alloy.