Mean stress sensitivity of spring steel in the very high cycle fatigue regime

Ultrasonic fatigue tests up to 1010 cycles were performed on a turbine engine titanium alloy (Ti-8Al-1Mo-1V) at the stress ratio (R) of −1 with smooth specimens and at R = −1, 0.1 and 0.5 with notched specimens. As a result, with increase of fatigue life, the source of reduced fatigue life caused by multi-point surface crack initiation changes from crack propagation stage to crack initiation stage in the high cycle fatigue regime. Notch effect further promotes the degeneration of high cycle and very high cycle fatigue strength at R > −1. The bilinear model, extended from the Goodman method, can better estimate the mean stress sensitivity of this titanium alloy. The fatigue mean stress sensitivity and fatigue-creep mean stress sensitivity of this material increased with the increase of fatigue life. The new model, based on the Murakami model, can provide more appropriate predictions for notch fatigue strength.

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OS0605 A Study on Very High Cycle Fatigue Properties of High Cleanliness Spring steel

The Proceedings of the Materials and Mechanics Conference ◽

10.1299/jsmemm.2011._os0605-1_ ◽

2011 ◽

Vol 2011 (0) ◽

pp. _OS0605-1_-_OS0605-3_

Author(s):

Tadayuki TANJI ◽

Masami WAKITA ◽

Shingo MIMURA ◽

Akira UENO ◽

Shoichi KIKUCHI ◽

...

Keyword(s):

High Cycle Fatigue ◽

Spring Steel ◽

Fatigue Properties ◽

Cycle Fatigue ◽

Very High Cycle Fatigue ◽

Very High

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The Effect of Compressive Mean Stress on Very High Cycle Fatigue Strength of Smooth Specimen of Aluminum Alloys

The Proceedings of the Materials and Mechanics Conference ◽

10.1299/jsmemm.2018.os0826 ◽

2018 ◽

Vol 2018 (0) ◽

pp. OS0826 ◽

Cited By ~ 1

Author(s):

Ukon KONO ◽

Shota HASUNUMA ◽

Takeshi OGAWA

Keyword(s):

Fatigue Strength ◽

Aluminum Alloys ◽

High Cycle Fatigue ◽

Mean Stress ◽

Smooth Specimen ◽

Cycle Fatigue ◽

Very High Cycle Fatigue ◽

Very High

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Very high cycle fatigue properties of high-strength spring steel 60SiCrV7

Fatigue & Fracture of Engineering Materials & Structures ◽

10.1111/ffe.12409 ◽

2016 ◽

Vol 39 (9) ◽

pp. 1081-1091 ◽

Cited By ~ 2

Author(s):

W. J. Hui ◽

C. Zhou ◽

Y. J. Zhang ◽

X. L. Zhao ◽

H. Dong

Keyword(s):

High Cycle Fatigue ◽

High Strength ◽

Spring Steel ◽

Fatigue Properties ◽

Cycle Fatigue ◽

Very High Cycle Fatigue ◽

Very High

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The influence of tension mean stress to the crack initiation process at the very high cycle fatigue regime for a high strength steel

MATEC Web of Conferences ◽

10.1051/matecconf/201816520001 ◽

2018 ◽

Vol 165 ◽

pp. 20001

Author(s):

Thomas Rohm ◽

Karl-Heinz Lang ◽

Marcus Korn

Keyword(s):

Crack Initiation ◽

High Strength Steel ◽

High Cycle Fatigue ◽

High Strength ◽

Mean Stress ◽

Cycle Fatigue ◽

Very High Cycle Fatigue ◽

Initiation Process ◽

Incremental Step ◽

Very High

Strain controlled tests were performed on a high strength steel to investigate the influence of tension mean stress to the crack initiation process at the very high cycle fatigue regime. It is supposed that the variation of stress the state in the vicinity of a non-metallic inclusion results in a change to the energy transferred to the surrounding metallic matrix. To prove this, incremental step tests on cylindrical specimen were realized in which the tension mean stress was stepwise increased. It could be verified that the hysteresis area, which is a criterion of the work transferred to the specimen, decreases with increasing tension mean stress. The test results provide a reasonable physical model to estimate the influence of tension mean stress to the crack initiation process in the very high cycle fatigue regime.

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