Evaluation of Multiaxial Fatigue Life Prediction Methodologies for Ti-6Al-4V

2002 ◽  
Vol 124 (2) ◽  
pp. 229-237 ◽  
Author(s):  
Alan R. Kallmeyer ◽  
Ahmo Krgo ◽  
Peter Kurath
Keyword(s):  
Fatigue Damage ◽  
Life Prediction ◽  
Equivalent Stress ◽  
Multiaxial Fatigue ◽  
Critical Plane ◽  
Proportional Loading ◽  
Biaxial Fatigue ◽  
Fatigue Data ◽  
Stress States ◽  
Mean Stresses

Many critical engineering components are routinely subjected to cyclic multiaxial stress states, which may include non-proportional loading and multidimensional mean stresses. Existing multiaxial fatigue models are examined to determine their suitability at estimating fatigue damage in Ti-6Al-4V under complex, multiaxial loading, with an emphasis on long-life conditions. Both proportional and non-proportional strain-controlled tension/torsion experiments were conducted on solid specimens. Several multiaxial fatigue damage parameters are evaluated based on their ability to correlate the biaxial fatigue data and uniaxial fatigue data with tensile mean stresses (R>−1) to a fully-reversed (R=−1) uniaxial baseline. Both equivalent stress-based models and critical plane approaches are evaluated. Only one equivalent stress model and two critical plane models showed promise for the range of loadings and material considered.

Development of a Multiaxial Fatigue Damage Model for High Strength Alloys Using a Critical Plane Methodology

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Matthew Erickson ◽  
Alan R. Kallmeyer ◽  
Robert H. Van Stone ◽  
Peter Kurath
Keyword(s):  
Crack Nucleation ◽  
Equivalent Stress ◽  
Damage Model ◽  
High Strength ◽  
Multiaxial Fatigue ◽  
Critical Plane ◽  
Load Paths ◽  
Fatigue Data ◽  
Definition Of ◽  
Mean Stresses

The prediction of fatigue life for metallic components subjected to complex multiaxial stress states is a challenging aspect in design. Equivalent-stress approaches often work reasonably well for uniaxial and proportional load paths; however, the analysis of nonproportional load paths brings forth complexities, such as the identification of cycles, definition of mean stresses, and phase shifts, that the equivalent-stress approaches have difficulties in modeling. Shear-stress based critical-plane approaches, which consider the orientation of the plane on which the crack is assumed to nucleate, have shown better success in correlating experimental results for a broader variety of load paths than equivalent-stress models. However, while the interpretation of the ancillary stress terms in a critical-plane parameter is generally straightforward within proportional loadings, there is often ambiguity in the definition when the loading is nonproportional. In this study, a thorough examination of the variables responsible for crack nucleation is presented in the context of the critical-plane methodology. Uniaxial and multiaxial fatigue data from Ti–6Al–4V and three other alloys, namely, Rene’104, Rene’88DT, and Direct Age 718, are used as the basis for the evaluation. The experimental fatigue data include axial, torsional, proportional, and a variety of nonproportional tension/torsion load paths. Specific attention is given to the effects of torsional mean stresses, the definition of the critical plane, and the interpretation of normal stress terms on the critical plane within nonproportional load paths. A new modification to a critical-plane parameter is presented, which provides a good correlation of experimental fatigue data.

Multiaxial Fatigue Damage Models

2006 ◽  
Vol 324-325 ◽  
pp. 747-750 ◽  
Author(s):  
De Guang Shang ◽  
Guo Qin Sun ◽  
Jing Deng ◽  
Chu Liang Yan
Keyword(s):  
Shear Strain ◽  
Fatigue Damage ◽  
Multiaxial Fatigue ◽  
Normal Strain ◽  
Critical Plane ◽  
Proportional Loading ◽  
Maximum Shear Strain ◽  
Damage Models ◽  
Thin Tube ◽  
Critical Plane Approach

Two multiaxial damage parameters are proposed in this paper. The proposed fatigue damage parameters do not include any weight constants, which can be used under either multiaxial proportional loading or non-proportional loading. On the basis of the research on the critical plane approach for the tension-torsion thin tubular multiaxial fatigue specimens, two multiaxial fatigue damage models are proposed by combining the maximum shear strain and the normal strain excursion between adjacent turning points of the maximum shear strain on the critical plane. The proposed multiaxial fatigue damage models are used to predict the fatigue lives of the tension-torsion thin tube, and the results show that a good agreement is demonstrated with experimental data.

scholarly journals Multiaxial Fatigue Life Prediction on S355 Structural and Offshore Steel Using the SKS Critical Plane Model

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1060 ◽  
Author(s):  
Alejandro Cruces ◽  
Pablo Lopez-Crespo ◽  
Belen Moreno ◽  
Fernando Antunes
Keyword(s):  
Life Prediction ◽  
High Cycle Fatigue ◽  
Low Cycle Fatigue ◽  
Damage Parameter ◽  
Multiaxial Fatigue ◽  
Cycle Fatigue ◽  
Critical Plane ◽  
Plane Model ◽  
Fatigue Data ◽  
Different Types

This work analyses the prediction capabilities of a recently developed critical plane model, called the SKS method. The study uses multiaxial fatigue data for S355-J2G3 steel, with in-phase and 90° out-of-phase sinusoidal axial-torsional straining in both the low cycle fatigue and high cycle fatigue ranges. The SKS damage parameter includes the effect of hardening, mean shear stress and the interaction between shear and normal stress on the critical plane. The collapse and the prediction capabilities of the SKS critical plane damage parameter are compared to well-established critical plane models, namely Wang-Brown, Fatemi-Socie, Liu I and Liu II models. The differences between models are discussed in detail from the basis of the methodology and the life results. The collapse capacity of the SKS damage parameter presents the best results. The SKS model produced the second-best results for the different types of multiaxial loads studied.

Life Prediction and Verification under Multiaxial Fatigue Loading

2013 ◽  
Vol 365-366 ◽  
pp. 991-994
Author(s):  
Lei Wang ◽  
Tian Zhong Sui ◽  
Qiu Cheng Tian
Keyword(s):  
Strain Amplitude ◽  
Life Prediction ◽  
Fatigue Loading ◽  
Multiaxial Fatigue ◽  
Normal Strain ◽  
Critical Plane ◽  
Proportional Loading ◽  
Maximum Shear Strain ◽  
Change Characteristics ◽  
Strain Change

The strain change characteristics of multiaxial fatigue are analyzed under the condition of the combined tension and torsion loading for thin-tube specimen. Based on the principle of multiaxial critical plane approach, a multiaxial fatigue damage parameter is established, which takes account of the effect of not only the maximum shear strain amplitude and normal strain amplitude on the critical plane but also the parameter of non-proportionality. The non-proportionality is the function of loading parameters which is closely contact with the strain change characteristics of multiaxial fatigue and it can indicate the whole material damage. The experiments under the tension-torsion proportional and non-proportional loading were conducted to verify the multiaxial fatigue life model proposed in this paper. The life prediction has a good correlation with the experimental results.

Life Prediction Techniques for Variable Amplitude Multiaxial Fatigue—Part 1: Theories

1996 ◽  
Vol 118 (3) ◽  
pp. 367-370 ◽  
Author(s):  
C. H. Wang ◽  
M. W. Brown
Keyword(s):  
Fatigue Damage ◽  
Life Prediction ◽  
Local Strain ◽  
Multiaxial Fatigue ◽  
Critical Plane ◽  
Random Loading ◽  
Variable Amplitude ◽  
Fatigue Damage Accumulation ◽  
Prediction Techniques ◽  
Searching Method

Fatigue life prediction under multiaxis random loading is an extremely complex and intractable topic; only a few methods have been proposed in the literature. In addition, experimental results under multiaxis random loading are also scarce. In part one of this two-part paper, a multiaxial non-proportional cycle counting method and fatigue damage calculation procedure are proposed, which is compared with one published damage-searching method. Both theories are based on critical plane concepts, one being an extension of the local strain approach for uniaxial variable amplitude loading and the other employing a new counting algorithm for multiaxis random loading. In principle, these two methods can be considered as bounding solutions for fatigue damage accumulation under multiaxis random loading.

Multiaxial Fatigue Life Prediction of Metallic Materials Based on Critical Plane Method under Non-Proportional Loading

2017 ◽  
Vol 730 ◽  
pp. 516-520 ◽  
Author(s):  
Er Nian Zhao ◽  
Wei Lian Qu
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Multiaxial Fatigue ◽  
Fatigue Life Prediction ◽  
Metallic Materials ◽  
Loading Conditions ◽  
Critical Plane ◽  
Proportional Loading ◽  
Plane Method ◽  
Strain Paths

The critical plane method is widely discussed because of its effectiveness for predicting the multiaxial fatigue life prediction of metallic materials under the non-proportional loading conditions. The aim of the present paper is to give a comparison of the applicability of the critical plane methods on multiaxial fatigue life prediction. A total of 205 multiaxial fatigue test data of nine kinds of metallic materials under various strain paths are adopted for the experimental verification. Results shows that the von Mises effective strain parameter and KBM critical plane parameter can give well predicted fatigue lives for multiaxial proportional loading conditions, but give poor prediction lives evaluation for multiaxial non-proportional loading conditions. However, FS parameter shows better accuracy than the KBM parameter for multiaxial fatigue prediction for both proportional and non-proportional loading conditions.

scholarly journals Multiaxial high-cycle fatigue modelling for random loading

2019 ◽  
Vol 300 ◽  
pp. 12005
Author(s):  
Haoyang Wei ◽  
Jie Chen ◽  
Patricio Carrion ◽  
Anahita Imanian ◽  
Nima Shamsaei ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Normal Stress ◽  
Life Prediction ◽  
Equivalent Stress ◽  
Multiaxial Fatigue ◽  
Fatigue Life Prediction ◽  
Load Spectrum ◽  
Critical Plane ◽  
Random Loading ◽  
Random Load

In this paper, a multiaxial fatigue life prediction model is proposed under general multiaxial random loadings. First, a brief review for existing multiaxial fatigue models is given and special focus is on the LiuMahadevan critical plane concept, which can be applied to both brittle and ductile materials. Next, new model development based on the Liu-Mahadevan critical plane concept for random loading is presented. The key concept is to use two-steps to identify the critical plane: identify the maximum damage plane due to normal stress and calculate the critical plane orientation with respect to the maximum damage plane due to normal stress. Multiaxial rain-flow cycle counting method with mean stress correction is used to estimate the damage on the critical plane. Equivalent stress transformation is proposed to convert the multiaxial random load spectrum to an equivalent constant amplitude spectrum. The equivalent stress is used for fatigue life prediction. Following this, experimental design and testing is performed for Al 7075-T6 under various different random uniaxial and multiaxial spectrums. The developed model is validated with both literature and in-house testing data. Very good agreement is observed for the investigated material. Finally, conclusion and future work is given based on the proposed study.

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