Finite element modelling and analysis of the burst margin of a gas turbine disc using an area weighted mean hoop stress method

One of the main failure modes of the turbine disc is formation of yield zone at bore which leads to burst of the disc. Hence, disc burst is treated as a critical factor while designing the disc. The scope of present work is to carry-out the elastic - plastic analysis and to find the burst margin of a typical model of a gas turbine disc by means of the finite-element technique for different speed of rotation. The additional goal of the analysis is to compare the burst margin of turbine disc having variable thickness and uniform thickness profile of the disc. The burst margin is estimated using area weighted mean hoop stress (AWMHS) approach. For given burst margin greater than 122%, the variable thickness disc provides lower operating speed in comparison to uniform thickness disc. This helps in reducing hoop stress, which is highly desirable in aero-engine.