Remaining Life Related Issues Being Pursued at DRDO for Indian Air Force

Hot section components of an aircraft gas turbine engine are critical to the performance and safety during the operation of military aircraft, where the service spectra are highly random and relatively severe in terms of the loading rates. DMRL, in collaboration with Indian Air Force (IAF), has initiated a project for the estimation of remaining life as well as life extension of military aeroengines of various origins. This is based on extensive laboratory specimen-level material characterization in terms of fatigue and creep, followed by the scale-up of experimental results to actual component. Finite Element Analysis (FEA) is an indispensable engineering tool for evaluation of the mechanical variables that determine crack initiation and growth, apart from material degradation prior to physical failure. DMRL's understanding and experience with FEA applications and damage mechanics concepts in these areas are briefly discussed in this paper.