Effects of an Artificial Small Defect on Torsional Fatigue Strength of Steels

1987 ◽  
Vol 109 (2) ◽  
pp. 124-129 ◽  
Author(s):  
Masahiro Endo ◽  
Yukitaka Murakami
Keyword(s):  
Fatigue Strength ◽  
Crack Propagation ◽  
Hole Diameter ◽  
Threshold Condition ◽  
Bending Fatigue ◽  
Torsional Fatigue ◽  
Small Defect ◽  
Bending Fatigue Test ◽  
Rotating Bending Fatigue ◽  
Rotating Bending

In order to elucidate the effect of small defects on the torsional fatigue strength of steels, reversed torsion tests were carried out on the 0.46 percent C steel specimens containing a small hole. The hole diameter ranges from 40 to 500μm. The fatigue behaviors on the specimen surface and near the hole were observed with the aid of a microscope. The torsional fatigue strength of steels containing small holes can be predicted from the results of rotating bending fatigue test by considering the threshold condition for crack propagation.

Improvement of Fatigue Strength of Aluminum Alloy by Cavitation Shotless Peening

2002 ◽  
Vol 124 (2) ◽  
pp. 135-139 ◽  
Author(s):  
Hitoshi Soyama ◽  
Kenichi Saito ◽  
Masumi Saka
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Strength ◽  
Shot Peening ◽  
High Speed ◽  
Bending Fatigue ◽  
Hydraulic Machinery ◽  
Bending Fatigue Test ◽  
Rotating Bending Fatigue ◽  
Rotating Bending ◽  
Cavitation Shotless Peening

Cavitation impact, which normally produces severe damage in hydraulic machinery, can be used to modify surfaces in the same way as shot peening. Cavitation impact enables the surface of a material to be peened without the use of shot, thus it is called cavitation shotless peening. As there are no solid body collisions occurring in this peening process, the roughness of the peened surface should be less than that produced by shot peening. This characteristic makes it suitable for peening soft metals. In order to demonstrate the improvement of the fatigue strength of aluminum alloy by this process, specimens were subjected to the process, and then tested in a rotating bending fatigue test. Cavitation impacts were produced and controlled by using a submerged high speed water jet with cavitation, i.e., a cavitating jet. It was revealed that the fatigue strength of an aluminum alloy specimen treated by this peening process was 50% stronger than that of a specimen without peening.

Experiment Research on the Influence of Fretting on Crack Propagation

2011 ◽  
Vol 228-229 ◽  
pp. 617-620 ◽  
Author(s):  
Guang Xue Yang ◽  
Qiang Li ◽  
Ji Long Xie
Keyword(s):  
Fatigue Life ◽  
Crack Propagation ◽  
Fretting Fatigue ◽  
Experimental Result ◽  
Test Machine ◽  
Bending Fatigue ◽  
Bending Fatigue Test ◽  
Rotating Bending Fatigue ◽  
Rotating Bending ◽  
Shrink Fit

In order to investigate the influence of fretting induced by a shrink-fit shaft and hub subjected to rotating bending on crack propagation on different position, small specimens consisted of shaft and hub were tested on the four point rotating bending fatigue test machine. The experimental result shows that the fretting fatigue life of specimen with notch outside the shaft-hub contact is shortest, and the fretting fatigue life of specimen with notch inside the shaft-hub contact is longest.

A FAST ROTATING BENDING FATIGUE TEST MACHINE

2017 ◽  
Author(s):  
Marco Antonio Meggiolaro ◽  
Jaime T P Castro ◽  
Rodrigo de Moura Nogueira
Keyword(s):  
Fatigue Test ◽  
Test Machine ◽  
Bending Fatigue ◽  
Bending Fatigue Test ◽  
Rotating Bending Fatigue ◽  
Rotating Bending ◽  
Fast Rotating

A Study onP-S-NCurve for Rotating Bending Fatigue Test for Bearing Steel

2008 ◽  
Vol 51 (2) ◽  
pp. 166-172 ◽  
Author(s):  
Katsuji Tosha ◽  
Daisuke Ueda ◽  
Hirokazu Shimoda ◽  
Shigeo Shimizu
Keyword(s):  
Fatigue Test ◽  
Bearing Steel ◽  
Bending Fatigue ◽  
Bending Fatigue Test ◽  
Rotating Bending Fatigue ◽  
Rotating Bending

High Cycle Fatigue Behavior of Thermally Oxidized Ti6Al4V Alloy

2007 ◽  
Vol 561-565 ◽  
pp. 2179-2182 ◽  
Author(s):  
Mehmet Cingi ◽  
Onur Meydanoglu ◽  
Hasan Guleryuz ◽  
Murat Baydogan ◽  
Huseyin Cimenoglu ◽  
...  
Keyword(s):  
Fatigue Strength ◽  
Yield Strength ◽  
Thermal Oxidation ◽  
Fatigue Behavior ◽  
Surface Hardness ◽  
Ti6al4v Alloy ◽  
Bending Fatigue ◽  
Rotating Bending Fatigue ◽  
Rotating Bending ◽  
Bending Fatigue Strength

In this study, the effect of thermal oxidation on the high cycle rotating bending fatigue behavior of Ti6Al4V alloy was investigated. Oxidation, which was performed at 600°C for 60 h in air, considerably improved the surface hardness and particularly the yield strength of the alloy without scarifying the tensile ductility. Unfortunately, the rotating bending fatigue strength at 5x106 cycles decreased from about 610 MPa to about 400 MPa upon oxidation. Thus, thermal oxidation leaded a reduction in the fatigue strength of around 34%, while improving the surface hardness (HV0.1) and yield strength 85 % and 36 %, respectively.

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