scholarly journals Evaluation of the Methods for Estimating the Fully Reversed Unnotched Fatigue Limits of Steels

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Jing Li ◽  
Yuan-ying Qiu ◽  
Hai-dong Wang ◽  
Zhao-xi Wang
Keyword(s):  
Tensile Properties ◽  
Fatigue Limit ◽  
Brinell Hardness ◽  
Estimation Method ◽  
Estimation Methods ◽  
Fatigue Properties ◽  
Empirical Relations ◽  
Strength Based ◽  
Deviation Criterion

Experimental determination of the fatigue limit is expensive considering the time and effort involved. To overcome this drawback, several empirical relations based on monotonic tensile properties and/or hardness have been developed for estimating the fatigue limit. In this study, ten estimation methods are evaluated and compared using the experimental data of 171 steels from literature. The scatter band criterion, standard deviation criterion, and statistical analysis are all used to evaluate and compare the predictability of the considered empirical relations. It is found that the fatigue limit can be well correlated with the Brinell hardness. In the absence of Brinell hardness, the ultimate tensile strength-based direct estimation method may be an alternative to estimate the fatigue limit of steels. It is not recommended to estimate the fatigue limit by using the indirect method on the basis of Basquin’s fatigue properties estimated by the monotonic tensile properties even though the fatigue limit of steel is often determined by the experimental Basquin’s curve at 106 cycles.

scholarly journals Fatigue Properties Estimation and Life Prediction for Steels under Axial, Torsional, and In-Phase Loading

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Ernian Zhao ◽  
Qiang Zhou ◽  
Weilian Qu ◽  
Wenming Wang
Keyword(s):  
Fatigue Test ◽  
Test Data ◽  
Prediction Accuracy ◽  
Life Prediction ◽  
Brinell Hardness ◽  
Estimation Method ◽  
Estimation Methods ◽  
Fatigue Properties ◽  
Engineering Structures ◽  
Advantages And Disadvantages

In this study, several estimation methods of fatigue properties based on different monotonic mechanical parameters were first discussed. The advantages and disadvantages of the Hardness Method proposed by Roessle and Fatemi were investigated and improved through the analysis of a total of 92 fatigue test data. A new Segment Fitting Method from Brinell hardness was then proposed for the fatigue properties estimation, and a total of 96 pieces of fatigue test data under axial, torsional, and multiaxial in-phase loading were collected to verify the applicability of the new proposal. Finally, the prediction accuracy of the new proposal and three exciting estimation methods was compared with the predictions based on the experimental fatigue properties. Based on the results obtained, the newly proposed estimation method has a significant improvement on the relation between fatigue ductility coefficient and Brinell hardness, which consequently improves the fatigue life prediction accuracy with the scatter band of 2, particularly for the materials with low Brinell hardness. The present study can provide a simplified analysis of the preliminary fatigue design of engineering structures.

scholarly journals Evaluation of Estimation Methods for Shear Fatigue Properties and Correlations with Uniaxial Fatigue Properties for Steels and Titanium Alloys

2018 ◽  
Vol 165 ◽  
pp. 16012 ◽  
Author(s):  
Shahriar Sharifimehr ◽  
Ali Fatemi
Keyword(s):  
Titanium Alloys ◽  
Inconel 718 ◽  
Fatigue Behavior ◽  
Estimation Method ◽  
Fatigue Tests ◽  
Estimation Methods ◽  
Fatigue Properties ◽  
Modified Method ◽  
Shear Fatigue ◽  
Von Mises

The goal of this study was to evaluate the accuracy of different methods in correlating uniaxial fatigue properties to shear fatigue properties, as well as finding a reliable estimation method which is able to predict the shear fatigue behavior of steels and titanium alloys from their monotonic properties. In order to do so, axial monotonic as well as axial and torsion fatigue tests were performed on two types of steel and a Ti-6Al-4V alloy. The results of these tests along with test results of 23 types of carbon steel, Inconel 718, and three types of titanium alloys commonly used in the industry were analyzed. It was found that von Mises and maximum principal strain criteria were able to effectively correlate uniaxial fatigue properties to shear fatigue properties for ductile and brittle behaving materials, respectively. Also, it was observed that for steels and Inconel 718 obtaining shear fatigue properties from uniaxial fatigue properties which are in turn calculated from Roessle-Fatemi estimation method resulted in reasonable estimations when compared to experimentally obtained uniaxial fatigue properties. Furthermore, a modification was made to the Roessle-Fatemi hardness method in order to adjust it to fatigue behavior of titanium alloys. The modified method, which was derived from uniaxial fatigue properties of titanium alloys with Brinell hardness between 240 and 353 proved to be accurate in predicting the shear fatigue behaviors.

Fatigue Strength and Life Estimation Methods Using Critical Distance Stress Theory

2013 ◽  
Vol 694-697 ◽  
pp. 853-863
Author(s):  
Muhammad Amiruddin Bin Ab Wahab ◽  
Niu Jie ◽  
Toshio Hattori ◽  
Minoru Yamashita
Keyword(s):  
Fatigue Life ◽  
Fatigue Limit ◽  
Low Cycle Fatigue ◽  
Estimation Method ◽  
Critical Distance ◽  
Estimation Methods ◽  
Cycle Fatigue ◽  
Limit Condition ◽  
Stress Theory ◽  
Two Parameters

Generallythe critical distance stress theory was applied for the fatigue limitestimation of general structures. In thismethod, it needs only two parameters, fatiguelimit of smooth specimen (σw0), and threshold stress intensityfactor range (∆Kth). In this paper we extended this method for theestimation of low cycle fatigue lifetoo. In this improvement wedefine the critical distance (rc’) on static strength conditions,which is calculated using ultimate tensile strength (σB) andfracture toughness (KIC), in addition to the critical distance onfatigue limit condition (rc). Then the critical distances of any lowcycle fatigue conditions can be calculated by interpolation of criticaldistance on fatigue limit (rc)with critical distance on staticstrength (rc’). By unifying these low cycle fatigue life estimationmethod with high cycle fatigue limit estimation method we can estimate the fullrange fatigue life easily. And to confirm the availabilityof this estimation method we perform the fatigue test for circlehole specimens, sharp V notch specimens andfretting fatigue specimens.

Using The Fully Modified M Method In Estimating The Effect Of Cultivated Area On Barley Production In Iraq For The Period 1970-2018

2020 ◽  
Vol 2020 (66) ◽  
pp. 101-110
Author(s):  
. Azhar Kadhim Jbarah ◽  
Prof Dr. Ahmed Shaker Mohammed
Keyword(s):  
Regression Model ◽  
Moving Average ◽  
Estimation Method ◽  
Estimation Methods ◽  
Autoregressive Moving Average ◽  
Moving Average Models ◽  
Error Terms ◽  
Relationship Of ◽  
The Relationship ◽  
Barley Crop

The research is concerned with estimating the effect of the cultivated area of barley crop on the production of that crop by estimating the regression model representing the relationship of these two variables. The results of the tests indicated that the time series of the response variable values is stationary and the series of values of the explanatory variable were nonstationary and that they were integrated of order one ( I(1) ), these tests also indicate that the random error terms are auto correlated and can be modeled according to the mixed autoregressive-moving average models ARMA(p,q), for these results we cannot use the classical estimation method to estimate our regression model, therefore, a fully modified M method was adopted, which is a robust estimation methods, The estimated results indicate a positive significant relation between the production of barley crop and cultivated area.

COPPER ALLOY No. 510

Alloy Digest ◽  
1971 ◽  
Vol 20 (8) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Low Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Copper Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Fatigue Properties ◽  
Temperature Performance ◽  
Tin Bronze

Abstract COPPER ALLOY No. 510 is a tin bronze containing about 0.25% phosphorus. It combines high strength and toughness with excellent fatigue properties. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep and fatigue. It also includes information on low temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-238. Producer or source: Brass mills.

TUNGUM ALLOY

Alloy Digest ◽  
2012 ◽  
Vol 61 (5) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Weight Ratio ◽  
High Strength ◽  
Fatigue Properties ◽  
Excellent Corrosion Resistance

Abstract Tungum alloy combines an unusually high strength-to-weight ratio, with ductility, excellent corrosion resistance, and good fatigue properties. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming. Filing Code: Cu-806. Producer or source: Tungum Ltd.

ANACONDA ALLOY (A) 5090

Alloy Digest ◽  
1979 ◽  
Vol 28 (5) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Chemical Industry ◽  
Heat Treating ◽  
Good Combination ◽  
Fatigue Properties ◽  
End Products

Abstract ANACONDA (A) 5090, long a specialty item in the industry, is a wrought intermediate phospor bronze developed to fulfill a need for special end-products such as kettles and other containers. It has found broad applications in the chemical industry. It offers a good combination of strength, ductility, resilience, fatigue properties and resistance to both corrosion and erosion. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-372. Producer or source: Anaconda American Brass Company.

RYCUT 50

Alloy Digest ◽  
1968 ◽  
Vol 17 (9) ◽  
Keyword(s):  
Physical Properties ◽  
Tensile Properties ◽  
Alloy Steel ◽  
Heat Treating ◽  
Molybdenum Alloy ◽  
Fatigue Properties

Abstract Rycut 50 is a leaded chromium-molybdenum alloy steel having high machinability rating combined with good tensile and fatigue properties. It is recommended for gears, shafts, bolts, and other machinery parts. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, machining, and joining. Filing Code: SA-230. Producer or source: Joseph T. Ryerson & Son Inc. (Distributor).

INLAND DURASPRING

Alloy Digest ◽  
1998 ◽  
Vol 47 (5) ◽  
Keyword(s):  
Fracture Toughness ◽  
Tensile Strength ◽  
Tensile Properties ◽  
High Stress ◽  
High Strength ◽  
Spring Steel ◽  
Fatigue Properties ◽  
Light Truck ◽  
Suspension Systems ◽  
Spring Steels

Abstract Inland DuraSpring is a high-strength microalloyed spring steel for use in high stress coil springs for automobile and light truck suspension systems. This bar product offers significant improvements in tensile strength, fatigue properties, and fracture toughness compared to conventional spring steels. This datasheet provides information on composition, hardness, and tensile properties as well asfracture toughness and fatigue. Filing Code: SA-496. Producer or source: Ispat Inland Inc.

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