A modified damage accumulation model for life prediction of aero‐engine materials under combined high and low cycle fatigue loading

Abstract

Aero-engine hot section components experience combined high and low cycle fatigue (CCF) loading under actual working conditions. This paper proposes a modified fatigue damage accumulation model to precisely predict lifetimes of aero-engine materials according to the newly presented interaction factor, which is able to quantitatively map damage interactions introduced by high cycle fatigue (HCF) and low cycle fatigue (LCF) loads. With the model, the lifetimes of four typical engine materials are predicted and compared to their factual data from experiments. The validation of the model is illustrated by a comprehensive comparison of the results concluded by the proposed model and that of other classical methodologies, which indicates that the new model holds the best performance in lifetime predictions. Moreover, an actual engineering case, which is the lifetime prediction of third stage turbine blades of an aero-engine, is completed to validate the feasibility of the proposed method.

On the consideration of loading interaction in combined high and low cycle fatigue life prediction

“…The increase in the number of high cycle loads superimposed on the low cycle loads will lead to a significant decrease in the fatigue life under CCF loading. The LCF life, HCF life, and stress amplitude of high and low cycle loading have a relatively large influence on the fatigue life under CCF loading, and the influence is complex; therefore, the specific laws are not easy to obtain through experiments 26–36 …”

“…The LCF life, HCF life, and stress amplitude of high and low cycle loading have a relatively large influence on the fatigue life under CCF loading, and the influence is complex; therefore, the specific laws are not easy to obtain through experiments. [26][27][28][29][30][31][32][33][34][35][36] In practical engineering applications, since the calculation method of Miner's rule is simple, and the estimated fatigue life error can meet manufacturing demand, it is often used to predict fatigue life. [37][38][39][40][41] With the improvement of the reliability requirements of the mechanical structure, the life prediction error by the Miner's rule has attracted widespread attention.…”

A Miner's rule based fatigue life prediction model for combined high and low cycle fatigue considering loading interaction effect

“…Under CCF loading, to calculate fatigue life, the Miner's rule has usually been introduced for its simplicity. Other researchers [31][32][33] proposed the life prediction model by taking into account the loading interaction effect. In view of the S-N curve and fatigue driving energy, Peng et al 34 described the fatigue failure process, proposing a nonlinear damage model within a high-cycle regime under variable amplitude loading.…”

“…The value of the threshold damage is dependent on the material constants obtained under CCF loadings. Bai et al 31 proposed a damage accumulation model considering the loading interaction effect by introducing an additional interaction factor that is fitted by the CCF test data. Zheng et al 40 proposed a CCF damage model to investigate the interaction between HCF and LCF for cast aluminum alloys, and the coupled damage contains some material constants determined from the fatigue interaction test.…”

Design and application testing of imaging probe for strain measurement

“…High precision equipment represented by high thrust-to-weight ratio aero-engines is an important symbol of national military power. Operating in complex environments characterized by high temperatures and pressures, these equipments are prone to stress concentration, fatigue, and even cracks [1][2][3], for example, the blades of an aero-engine work in high-temperature environments. Therefore, assessing the condition of such equipment is crucial to ensure its safety.…”