Analysis of revised fatigue life calculation algorithm under proportional and non-proportional loading with constant amplitude

This study presents a fatigue life prediction based on finite element analysis under non constant amplitude proportional loading. Parabolic spring is the vital component in a vehicle suspension system, commonly used in trucks. It needs to have excellent fatigue life and recently, manufacturers rely on constant loading fatigue data. The objective of this study is to simulate the non constant amplitude proportional loading for the fatigue life analysis. The finite element method (FEM) was performed on the spring model to observe the distribution of stress and damage. The fatigue life simulation was performed and analyzed for materials AISI6150, SAE1045-595-QT. when using the loading sequences is predominantly tensile in the nature; the life of mounting in Goodman approach is more conservative. When the loading is predominantly tensile in nature, the life of the component in Morrow approach is more sensitive and is therefore recommended. It can be concluded that material SAE 1045-595-QT gives constantly higher life than material AISI6150for all loading conditions under both methods.

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Multiaxial fatigue study on steel transversal attachments under constant amplitude proportional and non-proportional loadings

MATEC Web of Conferences ◽

10.1051/matecconf/201816516007 ◽

2018 ◽

Vol 165 ◽

pp. 16007

Author(s):

Martin Garcia ◽

Claudio A. Pereira Baptista ◽

Alain Nussbaumer

Keyword(s):

Fatigue Life ◽

High Strength ◽

Fatigue Tests ◽

Multiaxial Fatigue ◽

Life Assessment ◽

Experimental Program ◽

Proportional Loading ◽

Load Carrying ◽

Stress States ◽

Experimental Values

In this study, the multiaxial fatigue strength of full-scale transversal attachment is assessed and compared to original experimental results and others found in the literature. Mild strength S235JR steel is used and an exploratory investigation on the use of high strength S690QL steel and the effect of non-proportional loading is presented. The study focuses on non-load carrying fillet welds as commonly used in bridge design and more generally between main girders and struts. The experimental program includes 33 uniaxial and multiaxial fatigue tests and was partially carried out on a new multiaxial setup that allows proportional and non-proportional tests in a typical welded detail. The fatigue life is then compared with estimations obtained from local approaches with the help of 3D finite element models. The multiaxial fatigue life assessment with some of the well-known local approaches is shown to be suited to the analysis under multiaxial stress states. The accuracy of each models and approaches is compared to the experimental values considering all the previously cited parameters.

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Influence of Material Ductility on Fatigue Life under Multiaxial Proportional and Non-Proportional Normal and Shear Stresses

MATEC Web of Conferences ◽

10.1051/matecconf/201930017001 ◽

2019 ◽

Vol 300 ◽

pp. 17001 ◽

Cited By ~ 1

Author(s):

Cetin Morris Sonsino

Keyword(s):

Fatigue Life ◽

Tensile Elongation ◽

Shear Stresses ◽

Normal Strain ◽

Proportional Loading ◽

Ductile Materials ◽

Critical Components ◽

Material Ductility ◽

Fatigue Life Reduction ◽

Normal And Shear Stresses

Current experiences show that a non-proportional loading of ductile materials such as wrought steels, wrought aluminium or magnesium alloys, not welded or welded, causes a significant fatigue life reduction under an out-of-phase shear strain or shear stress superimposed on a normal strain or normal stress compared with proportional in-phase loading. However, when ductility, here characterised by tensile elongation, is reduced by a heat treatment or by another manufacturing technology such as casting or sintering, the afore-mentioned life reduction is compensated or even inversed, i. e. longer fatigue life results compared with proportional loading. Some actual results, determined with additive manufactured titanium, suggest that microstructural features such as manufacturing-dependent internal defects like microporosities should be considered in addition to the ductility level. This complex life behaviour under non-proportional loading cannot always be estimated. Therefore, in experimental proofs of multiaxial loaded parts, especially safety-critical components or structures, with real or service-like signals, emphasis must be placed on retaining non-proportionalities between loads and stresses/strains, respectively.

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Effects of Actual Marine Atmospheric Pre-Corrosion and Pre-Fatigue on the Fatigue Property of 7085 Aluminum Alloy

Metals ◽

10.3390/met12010081 ◽

2022 ◽

Vol 12 (1) ◽

pp. 81

Author(s):

Laixin Shi ◽

Lin Xiang ◽

Jianquan Tao ◽

Jun Liu ◽

Qiang Chen ◽

...

Keyword(s):

Aluminum Alloy ◽

Fatigue Life ◽

Pitting Corrosion ◽

Atmospheric Corrosion ◽

Fatigue Property ◽

Outdoor Exposure ◽

Fatigue Tests ◽

Constant Amplitude ◽

Fatigue Fractography ◽

Corrosion Mode

Effects of actual marine atmospheric precorrosion and prefatigue on the fatigue property of 7085-T7452 aluminum alloy were investigated by using the methods of marine atmospheric outdoor exposure tests and constant amplitude axial fatigue tests. Marine atmospheric corrosion morphologies, fatigue life, and fatigue fractography were analyzed. After three months of outdoor exposure, both pitting corrosion and intergranular corrosion (IGC) occurred, while the latter was the dominant marine atmospheric corrosion mode. Marine atmospheric precorrosion could result in a dramatical decrease in the fatigue life of the as-received 7085-T7452 aluminum alloy, while selective prefatigue can improve the total fatigue life of the precorroded specimen. The mechanism of the actual marine atmospheric corrosion and its effects on the fatigue life of the 7085-T7452 aluminum alloy were also discussed.

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104 Multiaxial Low Cycle Fatigue Life of Ti-6Al-4V under Non-proportional Loading

The Proceedings of Conference of Hokuriku-Shinetsu Branch ◽

10.1299/jsmehs.2009.46.7 ◽

2009 ◽

Vol 2009.46 (0) ◽

pp. 7-8

Author(s):

Yuuta SHIMIZU ◽

Takamoto ITOH ◽

Hiroshi NAKAMURA ◽

Masahiro TAKANASHI

Keyword(s):

Fatigue Life ◽

Low Cycle Fatigue ◽

Cycle Fatigue ◽

Proportional Loading

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Modification of Zenner and Liu Criterion due to Non-Proportionality of Fatigue Load by Means of MCE Approach

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.598.201 ◽

2014 ◽

Vol 598 ◽

pp. 201-206 ◽

Cited By ~ 1

Author(s):

Łukasz Pejkowski ◽

Dariusz Skibicki

Keyword(s):

Fatigue Life ◽

Experimental Verification ◽

Band 3 ◽

Damage Parameter ◽

Fatigue Load ◽

Proportional Loading ◽

Ellipse Method ◽

Multiple Materials

The results of experimental verification of Zenner and Lius criterion confirm its efficiency in the case of estimation of fatigue life for proportional loading. Due to application of general damage parameter, the criterion is useful in case of various types of proportional loading and for multiple materials. However, for non-proportional loadings, of high non-proportionality level, the error of estimation of fatigue lives often exceeds scatter band 3. The hereby work presents a proposal for Zenner and Lius criterion modification based upon introduction of loading non-proportionality measure with minimum circumscribed ellipse method (MCE).

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The Effects of Periodic High Loads on Fretting Fatigue

Journal of Engineering Materials and Technology ◽

10.1115/1.3225005 ◽

1981 ◽

Vol 103 (3) ◽

pp. 223-228 ◽

Cited By ~ 2

Author(s):

A. Kantimathi ◽

J. A. Alic

Keyword(s):

Aluminum Alloy ◽

Fatigue Life ◽

Growth Retardation ◽

Fretting Fatigue ◽

Fatigue Tests ◽

Constant Amplitude ◽

Axial Loads ◽

Prolonged Fatigue ◽

Stress Ratios ◽

Crack Growth Retardation

Fretting fatigue tests have been conducted on 7075-T7351 aluminum alloy coupons with fretting pads of the same material. Three different stress ratios were used, the otherwise constant amplitude axial loads being interrupted every 1000 cycles by either tensile overloads to 400 MPa or compressive underloads to −200 MPa. Tensile overloads greatly prolonged fatigue life for low stresses where the overload ratios were 1.6 and above; compressive underloads had comparatively little effect. The results are discussed in terms of crack growth retardation phenomena.

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