scholarly journals Validating the Methods to Process the Stress Path in Multiaxial High-Cycle Fatigue Criteria

Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 206
Author(s):  
Jan Papuga ◽  
Eva Cízová ◽  
Aleksander Karolczuk
Keyword(s):  
Fatigue Strength ◽  
Equivalent Stress ◽  
Stress Path ◽  
Multiaxial Fatigue ◽  
Moment Of Inertia ◽  
Critical Plane ◽  
Strength Criteria ◽  
Multiaxial Stress State ◽  
The Moment ◽  
Selection Of

The paper discusses one of the key features in the multiaxial fatigue strength evaluation—the procedure in which the stress path is analyzed to provide relevant measures of parameters required by multiaxial criteria. The selection of this procedure affects the complete equivalent stress derived for any multiaxial load combinations. Three major concepts—the minimum circumscribed circle, minimum circumscribed ellipse, and moment of inertia methods—are described. Analytical solutions of their evaluation for multiaxial stress state with components described by harmonic functions are provided. The concepts are validated on available experimental data when included into six different multiaxial fatigue strength criteria. The results show that the moment of inertia results in too conservative results. Differences between both methods of circumscribed entities are much smaller. There are indications however that the minimum circumscribed ellipse solution works better for critical plane criteria and for the criteria based on stress tensor transformation into the Ilyushin deviatoric space. On the other hand, the minimum circumscribed ellipse solution tends to shift integral criteria to the conservative side.

Effect of Non-Proportionality in the Fatigue Strength of 42CrMo4 Steel

2012 ◽  
Vol 730-732 ◽  
pp. 757-762
Author(s):  
Luís G. Reis ◽  
Vitor Anes ◽  
Bin Li ◽  
Manuel de Freitas
Keyword(s):  
Mechanical Properties ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Equivalent Stress ◽  
Multiaxial Fatigue ◽  
Loading Path ◽  
Mechanical Properties Of Materials ◽  
Degradation Of Mechanical Properties ◽  
42Crmo4 Steel ◽  
Properties Of Materials

The unexpected collapse of engineering structures is often caused by the fatigue phenomenon resulting from degradation of mechanical properties of materials due to multiaxial cyclic loadings. The interpretation of such degradation is a topic of intensive research in multiaxial fatigue. The fatigue strength is commonly evaluated by the equivalent stress based on the shear stress in the octahedral plane. However, the use of this kind of equivalent stress in the multiaxial fatigue criteria has been proven to be inappropriate. The degradation of mechanical properties of materials is dependent on several factors, e.g. the loading path has a strong influence on the fatigue strength. Non-proportional loadings cause higher damage in materials than proportional loadings for the same maximum equivalent stress. The purpose of this work is to study the effect of different multiaxial loadings on the 42CrMo4 steel and to improve the understanding about the relation between the fatigue strength and the sequential loading proportionality. The considered loadings were defined with the same history but with different load sequences and equivalent stress. To implement this work a biaxial servo-hydraulic fatigue machine was used. The fatigue life and crack angle were measured for each specimen. An analysis was made in order to correlate the crack initiation and fatigue life with the theoretical models, some remarks regarding these topics are presented.

scholarly journals A method for assessing wheel fatigue reliability considering multiaxial stress state

2020 ◽  
Vol 12 (1) ◽  
pp. 168781402090234
Author(s):  
Liuqing Yang ◽  
Ming Hu ◽  
Deming Zhao ◽  
Jing Yang ◽  
Xun Zhou
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
Equivalent Stress ◽  
Time Spectrum ◽  
Assessment Method ◽  
Multiaxial Fatigue ◽  
Rolling Contact ◽  
Fatigue Reliability ◽  
Multiaxial Stress State ◽  
Multiple Unit

Electric multiple unit is a modern transportation tool with high efficiency and large carrying capacity. Regarding its high speed, reliability requirement of the train is very important. As the main load bearing component of a train, the wheel is subjected to harsh working condition. Rolling contact between wheel and rail leads to wheel fatigue failure so that the fatigue reliability of wheel becomes one of the most attractive fields in electric multiple unit reliability study. This article proposed a fatigue reliability assessment method. It could obtain critical parts’ stress distribution efficiently through the force–stress relationship received by numerical simulation, so that it could assess wheel fatigue reliability under measured force–time spectrum. Also, multiaxial fatigue is considered in the method and the equivalent stress can be obtained by multiaxial model and fatigue experiment. Result of the case study shows that fatigue reliability of China Railway High-speed 5 wheel at 60,000 km mileage is 68%.

scholarly journals Validation of Multiaxial Fatigue Strength Criteria on Specimens from Structural Steel in the High-Cycle Fatigue Region

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 116
Author(s):  
František Fojtík ◽  
Jan Papuga ◽  
Martin Fusek ◽  
Radim Halama
Keyword(s):  
Fatigue Strength ◽  
Structural Steel ◽  
High Cycle Fatigue ◽  
Fatigue Loading ◽  
Multiaxial Fatigue ◽  
Experimental Results ◽  
Prediction Methods ◽  
Cycle Fatigue ◽  
Strength Criteria

The paper describes results of fatigue strength estimates by selected multiaxial fatigue strength criteria in the region of high-cycle fatigue, and compares them with own experimental results obtained on hollow specimens made from ČSN 41 1523 structural steel. The specimens were loaded by various combinations of load channels comprising push–pull, torsion, bending and inner and outer pressures. The prediction methods were validated on fatigue strengths at seven different numbers of cycles spanning from 100,000 to 10,000,000 cycles. No substantial deviation of results based on the selected lifetime was observed. The PCRN method and the QCP method provide best results compared with other assessed methods. The results of the MMP criterion that allows users to evaluate the multiaxial fatigue loading quickly are also of interest because the method provides results only slightly worse than the two best performing solutions.

Multiaxial fatigue assessment for outer cylinder of landing gear by critical plane method

2021 ◽  
pp. 095441002110260
Author(s):  
Yingyu Wang ◽  
Xiaofan Zhang ◽  
Xingliang Dong ◽  
Weixing Yao
Keyword(s):  
Outer Cylinder ◽  
Fatigue Loading ◽  
Landing Gear ◽  
Multiaxial Fatigue ◽  
Critical Plane ◽  
Proportional Loading ◽  
Fatigue Lifetime ◽  
Plane Method ◽  
Multiaxial Stress State ◽  
Maximum Variance

The in-service loadings on the landing gear are usually complex and from different directions, which lead to the fatigue critical locations in the landing gear structure mostly in multiaxial stress state. A methodology based on the critical plane method was proposed for estimating the fatigue lifetime of outer cylinder of the main landing gear undergoing variable amplitude (VA) multiaxial proportional loading. The orientation of the critical plane was determined by the so-called maximum variance method. The Bannantine–Socie’s cycle counting method and Miner’s linear rule were applied with Zhang–Yao’s criterion in this research. The calculated results on the fatigue lifetime of the outer cylinder were compared with the experimental data. The results indicate that the methodology proposed in this article is a sound method for fatigue life prediction of engineering components bearing complex VA multiaxial fatigue loading.

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.

scholarly journals Application of the Moment Of Inertia method to the Critical-Plane Approach

2016 ◽  
Vol 10 (38) ◽  
pp. 99-105 ◽  
Author(s):  
Hao Wu ◽  
Marco Antonio Meggiolaro ◽  
Jaime Tupiassú Pinho de Castro
Keyword(s):  
Moment Of Inertia ◽  
Critical Plane ◽  
Critical Plane Approach ◽  
The Moment

New strain energy-based critical plane approach for multiaxial fatigue life prediction

2019 ◽  
Vol 54 (5-6) ◽  
pp. 310-319
Author(s):  
Meng-Fei Hao ◽  
Shun-Peng Zhu ◽  
Ding Liao
Keyword(s):  
Fatigue Life ◽  
Strain Energy ◽  
Equivalent Stress ◽  
Equivalent Strain ◽  
Damage Parameter ◽  
Multiaxial Fatigue ◽  
Critical Plane ◽  
Critical Plane Approach ◽  
Energy Aspect ◽  
Life Predictions

Based on critical plane approach, this article develops a new damage parameter through combing the equivalent strain energy aspect for multiaxial fatigue analysis, which includes no additional fitted parameters and overcomes the deficiency of using only equivalent stress/strain criterion separately under multiaxial loadings. Then, experimental data of GH4169, TC4, Al 7050-T7451 alloys under different loading conditions are applied for model validation and comparison with other four models. Results indicate that the proposed damage parameter yields better multiaxial fatigue life predictions than others.

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.

Evaluation of data sets usable for validating multiaxial fatigue strength criteria

2021 ◽  
Vol 145 ◽  
pp. 106093 ◽  
Author(s):  
Jan Papuga ◽  
Adam Kaľavský ◽  
Maxim Lutovinov ◽  
Ivona Vízková ◽  
Slavomír Parma ◽  
...  
Keyword(s):  
Fatigue Strength ◽  
Multiaxial Fatigue ◽  
Data Sets ◽  
Strength Criteria ◽  
Evaluation Of Data

Using enclosing ellipsoids in multiaxial fatigue strength criteria

2006 ◽  
Vol 25 (1) ◽  
pp. 51-71 ◽  
Author(s):  
Nestor Zouain ◽  
Edgar Nobuo Mamiya ◽  
Fábio Comes
Keyword(s):  
Fatigue Strength ◽  
Multiaxial Fatigue ◽  
Strength Criteria
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