Reliability Analysis on a Turbine Disk Considering the Coupling of Multiple Failure Modes

Current probabilistic design methods mainly focus on single mode of failure, under the consideration on random variables including geometry, loading, and material properties. However, due to the complex structural characters and unevenly distributed temperature, turbine disks are always undergoing multiple potential failure modes, which should be effectively evaluated under a coupling scheme in reliability analysis. To this end, a collaborative response surface method involving multiple potential modes was established, aligning individual failure modes that were precisely evaluated via linear heteroscedastic regression analysis. To validate our model, reliability assessment was conducted on a turbine disk in turbo-shaft engine, where the coupling failure including low cycle fatigue and creep-fatigue was considered. This method can be an effective tool in the evaluation of reliability analysis involving multiple failure modes.