Fatigue reliability of gas turbine engine components under scheduledinspection maintenance

Abstract

A probabilistic method is developed for the fatigue reliability analysis of gas turbine engine components under scheduled inspection maintenance in service. Various statistical uncertainties involved in the complex design system of gas turbine engine components have been taken into account, including the time to crack initiation, fatigue crack propagation, service loads, crack modeling, crack geometry, nondestructive evaluation (NDE), etc. It is demonstrated that the service inspection maintenance can be used to improve the reliability of fatiguecritical components significantly. Such an improvement in fatigue reliability is shown to depend on the capability of the NDE system employed. An example for the third-stage turbine disk of a TF-33 jet engine has been worked out to demonstrate the application of the analysis methodology developed.

Probabilistic crack growth model for application to composite solid propellants

“…One way of increasing the crack growth resistance is to reduce the variability of the strength of the composite solid propellants. Equation (14) indicates that the crack growth rate is inversely proportional to p. The degree of the effect of (3 on the crack growth rate is shown in Fig. 5.…”

“…Again referring to Eq. (14), it can be seen that the average crack growth rate E [a] is a power function of the stress intensity factor K l9 with the exponent being equal to 2(1 + a" 1 ). In other words, the slope of the log E [a] vs log Kj curve is 2(1 + a" 1 ) and lies between 2.0 (when a = <*>) and 4.0 (when a = 1).…”

Fatigue reliability and sensitivity analysis of aero‐disk considering correlation

“…They utilized this probability model to analyze the fatigue reliability of typical engine components. 8 Gao et al presented a composite material fatigue reliability model considering the performance, which considers the comprehensive effects of performance degradation and effective stress growth, which can realize the fatigue reliability analysis of composites based on strength and stiffness. 9 Liu et al proposed a fatigue reliability assessment approach for wind turbine blades that combines finite element analysis to identify critical regions and quantify uncertainties with a continuous time Bayesian network model to analyze failure probabilities and relationships between blade components.…”

“…Yang and Chen suggested another probability model which incorporates various random factors that follow a logarithmic normal distribution, based on a deterministic model. They utilized this probability model to analyze the fatigue reliability of typical engine components 8 . Gao et al.…”