A New Energy-Critical Plane Damage Parameter for Multiaxial Fatigue Life Prediction of Turbine Blades

Abstract

As one of fracture critical components of an aircraft engine, accurate life prediction of a turbine blade to disk attachment is significant for ensuring the engine structural integrity and reliability. Fatigue failure of a turbine blade is often caused under multiaxial cyclic loadings at high temperatures. In this paper, considering different failure types, a new energy-critical plane damage parameter is proposed for multiaxial fatigue life prediction, and no extra fitted material constants will be needed for practical applications. Moreover, three multiaxial models with maximum damage parameters on the critical plane are evaluated under tension-compression and tension-torsion loadings. Experimental data of GH4169 under proportional and non-proportional fatigue loadings and a case study of a turbine disk-blade contact system are introduced for model validation. Results show that model predictions by Wang-Brown (WB) and Fatemi-Socie (FS) models with maximum damage parameters are conservative and acceptable. For the turbine disk-blade contact system, both of the proposed damage parameters and Smith-Watson-Topper (SWT) model show reasonably acceptable correlations with its field number of flight cycles. However, life estimations of the turbine blade reveal that the definition of the maximum damage parameter is not reasonable for the WB model but effective for both the FS and SWT models.

Using the Smith-Watson-Topper Parameter and Its Modifications to Calculate the Fatigue Life of Metals: The State-of-the-Art

“…Yu et al [ 36 ] formed a proposal in relation to the original form of SWT (5) expressed for strain and normal stress. In this model, the decisive factor for failure is the product of the maximum shear strains and the amplitude of these strains: where is maximum shear strain, is shear strain amplitude, and G is shear modulus.…”

Multiaxial fatigue under variable amplitude loadings: review and solutions

“…Several engineering components/structures normally operate under complex external loading conditions (Post et al ., 2008; Yu et al. , 2017a; Zhu et al ., 2018a, b, c, d; Liao et al ., 2019; Dantas et al.…”

“…Plastic shear strain 1. Introduction Several engineering components/structures normally operate under complex external loading conditions (Post et al, 2008;Yu et al, 2017a;Zhu et al, 2018a, b, c, d;Dantas et al, 2021;Niu et al, 2021a, b;Zhao et al, 2021;Zhu et al, 2021). In addition, the material defects, geometric discontinuities (notches), etc.…”

Fatigue life assessment of vehicle coil spring using finite element analysis under random strain loads in time domain

“…, 2019). Fatemi-Socie criteria substituting normal strain amplitude with maximum normal stress on critical plane and the analysis include material cyclic hardening effect (Yu et al. , 2017a,b).…”