Probabilistic failure risk assessment for aeroengine disks considering a transient process

One of the key processes for safety design of aeroengines is to accurately predict the failure risk of aeroengine disks. Current risk assessment methods mostly based on a constant stress are suitable for steady-state analysis but inappropriate for dangerous transient process. This work proposes a method of probabilistic failure risk assessment for aeroengine disks considering a transient process, and the core procedure is zone definition through refinement and further partition of a constant pre-zone based on the time-varying stress in a flight cycle. An aeroengine compressor disk is analyzed, and the failure risks of the disk considering a transient process and based on a steady-state design point are compared to examine the influence of the transient process on the failure risk of the disk. Results show that the failure risk considering the transient process is approximately 3.7 times of that based on the steady-state design point because the peak stress of the disk during the transient process exceeds the steady-state stress. The proposed method obtains more accurate predictions of failure risk, and is thus valuable for the safety design of aeroengines.