A unified reliability evaluation framework for aircraft turbine rotor considering multi-site failure correlation

Multiple dangerous sites often coexist in complex structures like aircraft turbine rotors, and its failure-correlated reliability evaluation usually occurs the thorny problems of high-efficacy computing and correlation quantification. In this paper, a novel unified reliability evaluation framework is proposed: to meet the high-efficacy computing demand of multi-site reliability evaluation, a new optimized Kriging surrogate-based improved importance sampling (OKS-IIS) method is first presented; furthermore, to quantify the failure correlation relationships among multiple dangerous sites, a novel failure correlation analysis (FCA) strategy is further developed. A typical reliability evaluation of high-pressure turbine rotor with multiple dangerous sites is selected, to validate the effectiveness of the proposed framework. Methods comparison show that the OKS-IIS method can improve computing efficiency while keeping computing accuracy, and the FCA strategy can accurately quantify the multi-site failure correlation. The current efforts would shed a light on the complex reliability evaluation problems involving failure correlation.