Designing Bearing Fatigue Life Tests for Improving the Use of Testing Resources

1989 ◽  
Vol 17 (3) ◽  
pp. 137
Author(s):  
A Wolfenden ◽  
B Miller ◽  
D Hester
Keyword(s):  
Fatigue Life ◽  
Life Tests

Tensile and Fatigue Failure of 17-4 PH Martensitic Stainless Steels in Presence of Hydrogen Depending on Frequency and Heat Treatment

2020 ◽  
Author(s):  
Jean-Gabriel Sezgin ◽  
Junichiro Yamabe
Keyword(s):  
Fatigue Life ◽  
Hydrogen Gas ◽  
Relative Reduction ◽  
Low Alloy Steels ◽  
Notched Specimen ◽  
Acceleration Ratio ◽  
Paris Law ◽  
Alloy Steels ◽  
Life Tests ◽  
Surface Morphologies

Abstract Slow-strain-rate tensile (SSRT) and fatigue-life tests were carried out on 17-4PH martensitic stainless steel with an ultimate tensile strength (UTS) of ∼ 1 GPa. The specimens were precharged by exposure to hydrogen gas at pressures of 35 MPa or 100 MPa at 270°C for 200 h. The SSRT tests used smooth axisymmetric specimens made of two grades of 17-4PH (H1150 and H900) differing by the UTS due to their thermal history. No degradation of the UTS was observed for both H1150 and H900 grades. However, the relative reduction in area (RRA) was 0.31 for H1150 or 0.11 for H900, translating a difference in their hydrogen sensitivity. Both grades presented different fracture-surface morphologies: a mixture of quasi-cleavage (QC) and intergranular (IG) facets for H1150 and cleavage (C) facets for H900. Circumferentially-notched axisymmetric specimens made of H1150 were used for the fatigue-life tests in the [10−3 Hz;10 Hz] frequency range. Our previous study on low-alloy steels with UTS of around 950 MPa demonstrates that the fatigue life of a circumferentially-notched specimen with a sharp notch can be successfully predicted from the fatigue crack growth (FCG) property following the Paris law. This study used the same specimen geometry and a BCC steel with a similar UTS value; hence, the FCG behavior was investigated from the fatigue-life test of the notched specimen. As a result, the degradation of fatigue lives attributed to the FCG acceleration was observed in presence of hydrogen. A FCG acceleration ratio bounded to 30 was observed in the high-cycle regime, accompanied by QC facets. A FCG acceleration ratio bounded to ∼100 was observed in the low-cycle regime, accompanied by QC and IG facets. A FCG model accounting for the interaction of elementary mechanisms was proposed and succeeded in predicting the FCG acceleration ratio observed on H1150. This model was also successfully applied to a low-alloy steel with a comparable UTS (1002 MPa) tested in gaseous hydrogen.

Comparison of the Experimental Results of the Calculation for Various Models of the Energy Parameter

2016 ◽  
Vol 250 ◽  
pp. 127-132
Author(s):  
Ewa Marcisz ◽  
Dariusz Rozumek
Keyword(s):  
Fatigue Life ◽  
Cross Section ◽  
Energy Parameter ◽  
Experimental Results ◽  
Elastic Model ◽  
Linear Elastic ◽  
Linear Elastic Model ◽  
Life Tests

The paper presents results of fatigue life tests conducted on transverse, circular and square cross-section specimens of C45 steel with controlled amplitude of energy parameter. The experimental results were compared with results obtained from computations on energy parameter models by R. Pawliczek, C. T. Lachowicz and on the linear-elastic model.

The Effect of Misalignment on the Fatigue Life of Tapered Roller Bearings

1972 ◽  
Vol 94 (2) ◽  
pp. 181-186 ◽  
Author(s):  
H. Zantopulos
Keyword(s):  
Experimental Study ◽  
Fatigue Life ◽  
Test Data ◽  
Load Distribution ◽  
Roller Bearings ◽  
Bearing Life ◽  
Life Tests ◽  
Tapered Roller ◽  
Tapered Roller Bearings ◽  
Sufficient Test

A comprehensive analytical and experimental study of the effect of misalignment on load distribution and fatigue life of tapered roller bearings is presented. Included are the effects of truncation of crowned rollers and edge of contact stresses. Bearing life tests, involving approximately 500 bearings, were run at various loads and misalignments to obtain sufficient test data to substantiate the analytical results.

Bearing Fatigue Life Tests in a Synthetic Traction Lubricant

1976 ◽  
Vol 19 (3) ◽  
pp. 250-256 ◽  
Author(s):  
D. V. Culp ◽  
J. D. Stover
Keyword(s):  
Fatigue Life ◽  
Life Tests

126 Bearing Fatigue Life Tests for Advanced Space Lubricants under Vacuum Condition

2010 ◽  
Vol 2010.18 (0) ◽  
pp. _126-1_-_126-5_
Author(s):  
Nobuyoshi OHNO ◽  
Hiroyuki TSUCHIDA ◽  
Shigeki MORITA ◽  
Hiroshi SHIOMI ◽  
Shingo OBARA
Keyword(s):  
Fatigue Life ◽  
Vacuum Condition ◽  
Life Tests

The Corrosion Fatigue Life Research of Shot Peening Aluminum Alloy

2011 ◽  
Vol 366 ◽  
pp. 19-23
Author(s):  
Song Li ◽  
You Cui ◽  
Sheng Li Lv ◽  
Wei Zhang ◽  
Xiao Yan Tong
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Mass Loss ◽  
Significant Influence ◽  
Shot Peening ◽  
Corrosion Damage ◽  
Residual Fatigue Life ◽  
Contrast Analysis ◽  
Life Tests ◽  
Residual Fatigue

The corrosion is one kind of major damage mechanisms of airplane structure and is also one of the primary causes resulting in flight failure and disaster .The aim of this paper is to analyze the effect of corrosion time on denudation depth, mass loss and the total depth of corrosion damage. Meanwhile, the three parameters have significant influence on residual fatigue life of aluminum alloy, the residual fatigue life of the aluminum alloy is of great difference between shot peening and without shot peening aluminum alloy. Then residual fatigue life tests are carried on Instron 8801 for the shot peening and without shot peening aluminum alloy. Based on contrast analysis of the experimental results, valuable conclusions are obtained: with the increase of the denudation depth, mass loss and the total depth of corrosion damage, fatigue life reduce continuously respectively; Fatigue life decreases rapidly when the denudation depth is in the range of 0.12～0.17mm.

Fatigue Life Calculation in Conditions of Wide Spectrum Random Loadings – The Experimental Verification of a Calculation Algorithm on the Example of 41Cr4 Steel

2012 ◽  
Vol 726 ◽  
pp. 17-26
Author(s):  
Bogdan Ligaj ◽  
Grzegorz Szala
Keyword(s):  
Fatigue Life ◽  
Wide Spectrum ◽  
Loading Conditions ◽  
Test Results ◽  
Structural Elements ◽  
Random Loading ◽  
Calculation Algorithm ◽  
Fatigue Characteristic ◽  
Life Tests ◽  
Fatigue Characteristics

Precision of fatigue life calculations of structural elements in programmed loading conditions is connected with proper elaboration of loading spectrum and assumption of a proper fatigue characteristic. On the base of literature data and own research there has been elaborated an algorithm for fatigue life calculations in random loading conditions with wide spectrum. Calculations were performed with the usage of chosen mathematical models of two-parametric fatigue characteristics. Results calculated with accordance to the described procedure were validated with experimental test results of specimens made of 41Cr4 steel with a method of programmed fatigue life tests.

Influence of Fiber Orientation and Volume Fraction on Tensile Strength and Fatigue Life of CARALL Hybrid Composite

2007 ◽  
Vol 353-358 ◽  
pp. 1455-1458 ◽  
Author(s):  
Han Ki Yoon
Keyword(s):  
Tensile Strength ◽  
Fatigue Life ◽  
Carbon Fiber ◽  
Hybrid Composite ◽  
Fiber Orientation ◽  
Small Volume ◽  
Volume Fraction ◽  
Volume Ratio ◽  
Fiber Direction ◽  
Life Tests

In this paper the tensile and fatigue life tests of carbon fiber-reinforced epoxy prepreg (CFRP) were conducted in order to investigate the influence of volume ratio and fiber orientation. CFRP/Al7075 laminate hybrid composite (CARALL) consists of alternating Al7075-T6 sheets and carbon epoxy prepreg (epoxy 121oC #2560). The fiber orientations of CFRP were applied to the extent of 0/90° and ±45°. The CFRP layers are 1ply, 3plies and 5plies in case of 0/90°, and 1ply and 2plies in case of ±45° of carbon fiber direction, respectively. The tensile strength decreased with the volume ratio of CFRP in both the cases of fiber orientation 0/90° and ±45°. The fatigue life is lower in large volume ratio of CFRP than in small volume ratio in both the cases of fiber orientation 0/90° and ±45°.

Reduction in Fatigue Life in Cr-Coated Steel Induced by Pulsed Laser Heating

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Jeffrey M. Warrender ◽  
Gregory N. Vigilante
Keyword(s):  
Fatigue Life ◽  
Crack Propagation ◽  
Pulsed Laser ◽  
Coated Steel ◽  
Propagation Behavior ◽  
Life Tests ◽  
Point Bend ◽  
Thermomechanical Processes ◽  
Laser Heated ◽  
Pulsed Laser Heating

Four-point bend tests were performed on Cr-coated steel specimens that were pulsed laser heated (PLH) with two pulses per area from a millisecond pulse duration laser. Cracks were observed in the PLH specimens extending to the substrate. Specimens subjected to PLH exhibited reduced cycles to failure under all the loadings. This indicates that the PLH process replaces the crack initiation process, and the PLH-formed cracks give the expected crack propagation behavior. This approach provides a method to separately study the effects of crack formation and crack propagation in fatigue life tests. It is especially applicable to situations in which the cracks to be propagated are induced by thermomechanical processes.

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