A General Criterion for Low-Cycle Multiaxial Fatigue Failure

1989 ◽  
Vol 111 (3) ◽  
pp. 263-269 ◽  
Author(s):  
A. Makinde ◽  
K. W. Neale
Keyword(s):  
Shear Strain ◽  
Fatigue Failure ◽  
Low Cycle Fatigue ◽  
Multiaxial Fatigue ◽  
General Criterion ◽  
Cycle Fatigue ◽  
Maximum Shear Strain ◽  
Number Of Cycles ◽  
New Criterion ◽  
Cycles To Failure

A new, general criterion is proposed for multiaxial low-cycle fatigue failure. Contours of constant fatigue life on a plot of maximum shear strain against the tensile strain acting normal to the plane of maximum shear strain are represented by a parametric criterion of the form g(θ,Nf)=kf1(θ)f2(Nf). Here g is the magnitude of the vector from the origin to a point on the constant life contour, θ is the angle associated with g in this space, Nf is the number of cycles to failure, k is a constant and f1 (θ) and f2(Nf) are two separate functions of θ and Nf, respectively. It is shown that all previously proposed macroscopic criteria are particular cases of the failure function g(θ, Nf). Experimental results from several authors are analyzed using the new criterion.

An Experimental Evaluation for Four Multiaxial Fatigue Approaches

2014 ◽  
Vol 627 ◽  
pp. 425-428
Author(s):  
Dan Jin ◽  
Da Jiang Tian ◽  
Qi Zhou Wu ◽  
Wei Lin
Keyword(s):  
Low Cycle Fatigue ◽  
Multiaxial Fatigue ◽  
304 Stainless Steel ◽  
Normal Strain ◽  
Cycle Fatigue ◽  
Critical Plane ◽  
Maximum Shear Strain ◽  
Rainflow Cycle Counting ◽  
Tubular Specimens ◽  
Damage Rule

A series of tests for low cycle fatigue were conducted on the tubular specimens for 304 stainless steel under variable amplitude and irregular axial-torsional loading. Rainflow cycle counting and linear damage rule are used to calculate fatigue damage and four approaches, e.g. SWT(Smith-Watson-Topper), KBM(Kandil-Brown-Miller), FS(Fatemi-Socie), and LKN(Lee-Kim-Nam) approach are employed to predict the fatigue life. The maximum shear strain plane, the maximum normal strain plane, and the maximum damage plane are considered as the critical plane, respectively. The effects of the choice of the critical plane on previous approaches are discussed. It is shown that comparing with the maximum shear/normal strain approach, the predictions are improved by using the maximum damage plane approach, part nonproportional paths for SWT, AV and part nonproportional paths for KBM, TV paths for FS. But for LKN, the prediction results are nonconservative for some paths than that of the maximum shear/normal strain approach.

scholarly journals Application of Differential Entropy in Characterizing the Deformation Inhomogeneity and Life Prediction of Low-Cycle Fatigue of Metals

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1917 ◽  
Author(s):  
Mu-Hang Zhang ◽  
Xiao-Hong Shen ◽  
Lei He ◽  
Ke-Shi Zhang
Keyword(s):  
Fatigue Failure ◽  
Low Cycle Fatigue ◽  
Pure Copper ◽  
Cyclic Strain ◽  
Material Model ◽  
Cycle Fatigue ◽  
Nickel Based Superalloy ◽  
Deformation Inhomogeneity ◽  
Tension Peak ◽  
Number Of Cycles

The relation between deformation inhomogeneity and low-cycle-fatigue failure of T2 pure copper and the nickel-based superalloy GH4169 under symmetric tension-compression cyclic strain loading is investigated by using a polycrystal representative volume element (RVE) as the material model. The anisotropic behavior of grains and the strain fields are calculated by crystal plasticity, taking the Bauschinger effect into account to track the process of strain cycles of metals, and the Shannon’s differential entropies of both distributions of the strain in the loading direction and the first principal strain are employed at the tension peak of the cycles as measuring parameters of strain inhomogeneity. Both parameters are found to increase in value with increments in the number of cycles and they have critical values for predicting the material’s fatigue failure. Compared to the fatigue test data, it is verified that both parameters measured by Shannon’s differential entropies can be used as fatigue indicating parameters (FIPs) to predict the low cycle fatigue life of metal.

An Experimental Study on Low Cycle Fatigue of Inconel 617 Super Alloy

2006 ◽  
Vol 306-308 ◽  
pp. 163-168 ◽  
Author(s):  
Jae Hoon Kim ◽  
Duck Hoi Kim ◽  
Young Shin Lee ◽  
Young Jin Choi ◽  
Hyun Soo Kim ◽  
...  
Keyword(s):  
Strain Energy ◽  
Low Cycle Fatigue ◽  
Cyclic Hardening ◽  
Fatigue Tests ◽  
Cyclic Behavior ◽  
Cycle Fatigue ◽  
Inconel 617 ◽  
Number Of Cycles ◽  
Cycles To Failure ◽  
Super Alloy

Low cycle fatigue tests are performed on the Inconel 617 super alloy that be used for structural material of hot gas casing for gas turbine. The relations between strain energy density and number of cycles to failure are examined in order to predict the low cycle fatigue life of Inconel 617 super alloy. The lives predicted by strain energy methods are found to coincide with experimental data and results obtained from the Coffin-Manson method. And, the cyclic behavior of the Inconel 617 super alloy is characterized by cyclic hardening with increasing number of cycles.

scholarly journals A novel model for low-cycle multiaxial fatigue life prediction based on the critical plane-damage parameter

2020 ◽  
Vol 103 (3) ◽  
pp. 003685042093622
Author(s):  
Jianhui Liu ◽  
Xin Lv ◽  
Yaobing Wei ◽  
Xuemei Pan ◽  
Yifan Jin ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Failure Mechanism ◽  
Fatigue Failure ◽  
Prediction Accuracy ◽  
Life Prediction ◽  
Low Cycle Fatigue ◽  
Multiaxial Fatigue ◽  
Fatigue Life Prediction ◽  
Cycle Fatigue ◽  
Classic Model

Multiaxial fatigue of the components is a very complex behavior. This analyzes the multiaxial fatigue failure mechanism, reviews and compares the advantages and disadvantages of the classic model. The fatigue failure mechanism and fatigue life under multiaxial loading are derived through theoretical analysis and formulas, and finally verified with the results of multiaxial fatigue tests. The model of multiaxial fatigue life for low-cycle fatigue life prediction model not only improves the prediction accuracy of the classic model, but also considers the effects of non-proportional additional hardening phenomena and fatigue failure modes. The model is proved to be effective in low-cycle fatigue life prediction under different loading paths and types for different materials. Compared with the other three classical models, the proposed model has higher life prediction accuracy and good engineering applicability.

Effect of Composition and Microstructure on the Low Cycle Fatigue Strength of Structural Steels

1965 ◽  
Vol 87 (2) ◽  
pp. 269-274 ◽  
Author(s):  
R. D. Stout ◽  
A. W. Pense
Keyword(s):  
Low Cycle Fatigue ◽  
Strain Range ◽  
Structural Steels ◽  
Cycle Life ◽  
Total Strain ◽  
Cycle Fatigue ◽  
Fatigue Data ◽  
Number Of Cycles ◽  
Relationship Of ◽  
Cycles To Failure

In a number of studies of data obtained from fatigue tests on various materials it has been shown that the number of cycles to failure is related to the strain range by a relationship of the form εNm=c where N is the number of cycles to failure, ε the strain range, and m and c are constants. In the low cycle portion of the strain range versus cycles to failure curve, evidence has been presented by several investigators to show that the relationship should be εpN1/2=c where εp is the plastic strain range and c, the constant, can be related to tensile ductility. Some investigators have found the relation εtNm=c more useful. Here εt is the total strain range. As a result of a series of Pressure Vessel Research Committee investigations at Lehigh University, a large body of low cycle fatigue data has been obtained for a wide range of steels, microstructures, heat-treatments, and testing conditions. A study of these data has been undertaken, with special emphasis on the suitability of a relationship of this type for analysis and representation of fatigue data. As a result of this study the following conclusions have been drawn: (a) In the range of 5000 to 100,000 cycles a relation εtNm = c appears to be satisfactory. (b) Using this latter relation, an analysis of the low cycle fatigue behavior of structural steels reveals that they can be classified into three broad groups on the basis of their composition. Each group has a characteristic value of m and c which can be used to predict their behavior over the range 5000–100,000 cycles. (c) The value of m and the total strain for 5000 cycle life can be related to n, the strain hardening exponent, for the steels. The total strain for 100,000 cycle life is related to the ultimate tensile strength of the steels. Using these relationships, the fatigue curve for a structural steel can be estimated from tension test data. (d) The effect of microstructural variations for a steel within any one of the three groups was of secondary importance when compared to the compositional groupings, although some systematic effects of microstructural variations were noted.

Numerical and Analytical Studies of Low Cycle Fatigue Behavior of 316 LN Austenitic Stainless Steel

2020 ◽  
Author(s):  
Ikram Abarkan ◽  
Rabee Shamass ◽  
Zineb Achegaf ◽  
Abdellatif Khamlichi
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Austenitic Stainless Steel ◽  
Shear Strain ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cycle Fatigue ◽  
Maximum Shear Strain ◽  
Conservative Estimation ◽  
316 Ln Ss

Abstract Mechanical components are frequently subjected to severe cyclic pressure and/or temperature loadings. Therefore, numerical and analytical low cycle fatigue methods become widely used in the field of engineering to estimate the design fatigue lives. The primary aim of this work is to evaluate the accuracy of the most commonly used numerical and analytical low cycle fatigue life methods for specimens made of 316 LN austenitic stainless steel and subjected to fully reversed uniaxial tension-compression loading, in the room temperature condition. It was found that both Maximum shear strain and Brown-Miller criterions result in a very conservative estimation for uniaxially loaded specimens, however, Maximum shear strain criteria provides better results compared to the Brown-Miller criteria. The total strain energy density approach was also used, and both the Masing and non-Masing analysis were adopted in this study. It is found that the Masing model provides conservative fatigue lives, and non-Masing model results in a more realistic fatigue life prediction for 316 LN stainless steel for both low and high strain amplitude. The fatigue design curves obtained from the commonly used analytical low cycle fatigue equations were reexamined for 316 LN SS. The obtained design curves from Langer model and its modified versions are non-conservative for this type of material. Consequently, the authors suggest new optimized parameters to fit the given test data. The obtained curve using the currently suggested parameters is in better agreement with the experimental data for 316 LN SS.

Low-Cycle Fatigue of Two Nickel-Base Alloys by Thermal-Stress Cycling

1960 ◽  
Vol 82 (3) ◽  
pp. 661-670 ◽  
Author(s):  
F. J. Mehringer ◽  
R. P. Felgar
Keyword(s):  
Thermal Stress ◽  
Thermal Stresses ◽  
Low Cycle Fatigue ◽  
Plastic Strains ◽  
Cycle Fatigue ◽  
Cyclic Life ◽  
Stress Cycling ◽  
Nickel Base ◽  
Number Of Cycles ◽  
Cycles To Failure

Cast DCM and cast Udimet 500, two nickel-base alloys, were tested in a thermal-stress-cycling device of the Coffin type. The strains induced by the thermal stresses were analyzed in several ways in an attempt to relate the plastic strains to cyclic life. The plastic strains were too small to permit calculating them with sufficient accuracy to correlate with cyclic life. It was found, however, that stress range did correlate reasonably well with the number of cycles to failure.

Crack mode and life of Ti-6Al-4V under multiaxial low cycle fatigue

2015 ◽  
Author(s):  
Takamoto Itoh ◽  
Masao Sakane ◽  
Takahiro Morishita ◽  
Hiroshi Nakamura ◽  
Masahiro Takanashi
Keyword(s):  
Hollow Cylinder ◽  
Stress Ratio ◽  
Biaxial Loading ◽  
Fatigue Testing ◽  
Low Cycle Fatigue ◽  
Testing Machine ◽  
Multiaxial Fatigue ◽  
Cycle Fatigue ◽  
Loading Test ◽  
Failure Life

This paper studies multiaxial low cycle fatigue crack mode and failure life of Ti-6Al-4V. Stress controlled fatigue tests were carried out using a hollow cylinder specimen under multiaxial loadings of ?=0, 0.4, 0.5 and 1 of which stress ratio R=0 at room temperature. ? is a principal stress ratio and is defined as ?=sigmaII/sigmaI, where sigmaI and sigmaII are principal stresses of which absolute values take the largest and middle ones, respectively. Here, the test at ?=0 is a uniaxial loading test and that at ?=1 an equi-biaxial loading test. A testing machine employed is a newly developed multiaxial fatigue testing machine which can apply push-pull and reversed torsion loadings with inner pressure onto the hollow cylinder specimen. Based on the obtained results, this study discusses evaluation of the biaxial low cycle fatigue life and crack mode. Failure life is reduced with increasing ? induced by cyclic ratcheting. The crack mode is affected by the surface condition of cut-machining and the failure life depends on the crack mode in the multiaxial loading largely.

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