EFFECTS OF RESIDUAL STRESSES CAUSED BY TURNING ON PROBABILISTIC RISK OF AEROENGINE TITANIUM DISKS

The residual stresses generated during the manufacturing process of aero-engine life-limited parts, such as turbine disks, affect the formation of cracks and thus influence the risk of failure. This study proposes a probabilistic risk assessment method for titanium aero-engine disks considering the residual stresses caused by turning. Specifically, a turning simulation model is firstly established by ABAQUS, and the residual stresses on the turning surface are obtained by conducting numerical analysis. Then, with the work stresses of a typical titanium turbine disk, the residual stresses are input into the failure probability evaluation model. Last, based on linear elastic fracture mechanics analysis, the crack propagation calculation is conducted, and the probabilities of failure of the disk are carried out. The results show that after considering residual stresses introduced by turning, the failure risk of the disk has declined. The probability of failure is predicted to reduce by nearly 8% under turning. The proposed method predicts the failure risk more accurately and is thus beneficial to the guidelines for the safety assessment of turbine disks.