Multiaxial Fatigue Damage Parameter and Life Prediction without Any Additional Material Constants

Abstract

Based on the critical plane approach, a simple and efficient multiaxial fatigue damage parameter with no additional material constants is proposed for life prediction under uniaxial/multiaxial proportional and/or non-proportional loadings for titanium alloy TC4 and nickel-based superalloy GH4169. Moreover, two modified Ince-Glinka fatigue damage parameters are put forward and evaluated under different load paths. Results show that the generalized strain amplitude model provides less accurate life predictions in the high cycle life regime and is better for life prediction in the low cycle life regime; however, the generalized strain energy model is relatively better for high cycle life prediction and is conservative for low cycle life prediction under multiaxial loadings. In addition, the Fatemi–Socie model is introduced for model comparison and its additional material parameter k is found to not be a constant and its usage is discussed. Finally, model comparison and prediction error analysis are used to illustrate the superiority of the proposed damage parameter in multiaxial fatigue life prediction of the two aviation alloys under various loadings.

Online multiaxial fatigue damage evaluation method by real‐time cycle counting and energy‐based critical plane criterion

“…To consider all the stress and strain components contributed to the fatigue damage on the critical plane, the generalized strain amplitude (GSA) model and the modified GSA (MGSA) model have been proposed by Ince‐Glinka and Yu, respectively, which are expressed as follows. where τ max and σ n ,max are the maximum shear stress and normal stress, respectively; Δ γ e /2 and are the elastic shear strain amplitude and the elastic normal strain amplitude, respectively; Δ γ p /2 and are the plastic shear strain amplitude and the plastic normal strain amplitude, respectively; and are the fatigue strength coefficient and the shear fatigue strength coefficient, respectively; and f 1 ( N f ) is the function with respect to the number of cycles to failure N f .…”

“…Analyzing the predicted results of the MGSA damage parameter in Yu et al and the GSA damage parameter in Ince and Glinka, a definite conclusion can be obtained that the MGSA model provides relatively nonconservative predictions compared with the GSA model. That is, in the MGSA model, the normalization of the plastic strain terms in Equation can make the predictions nonconservative.…”

“…Because the proposed damage parameter is based on the shear work and the maximum normal stress on the maximum shear strain range plane is zero in the case of pure shear fatigue, the equivalent maximum shear stress parameter can be correlated to the number of cycles to failure N f as …”

Remaining Useful Life Estimation of Aircraft Engines Using a Modified Similarity and Supporting Vector Machine (SVM) Approach

“…Suspension history condition monitoring data usually contain useful information revealing the degradation situation of the system, including environmental factors and loading variations in actual situations, such as degradations and variations of stress amplitudes [10][11][12]34,35]. If these data are properly used, it is helpful to estimate RUL more accurately, particularly when the failure data are insufficient and unavailable in some cases [36,37]. Li et al [38] used the suspension data to promote the prediction precision of a neural network.…”

Total fatigue life analysis of a nodular cast iron plate specimen with a center notch

“…New multiaxial approaches are being developed based on the critical plane method using local strain energy. 12,13 The probabilistic method of Zhu et al 14 is capable of considering the usual scatter found in material parameters in the multiaxial low-cycle fatigue (LCF) assessment. Special attention has been given lately to the fatigue assessment of components operating under high temperatures.…”