Study on vibration fatigue life prediction and reliability evaluation method of turbo-pump considering structural characteristics

The structural characteristics of the turbo-pump impeller in a liquid rocket engine are integrated into a vibration fatigue life model. Based on this model, a dual-layer evaluation model for the vibration fatigue life reliability of the turbo-pump structure is developed, accounting for parameter dispersion. This model advances a more universal and quantifiable prediction approach for structural vibration fatigue life, incorporating a high-reliability material S-N characteristic identification method that considers structural nuances. The efficacy of this model and the associated reliability evaluation method is demonstrated through tests on two types of turbo-pump impeller products, confirming their capability to accurately identify the S-N characteristics and their parameter dispersion. Furthermore, the life distribution law under varying levels of reliability is determined. The results underscore the significant application value of this method in predicting and evaluating the fatigue life of typical structures within rocket engines.