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Experimental Mechanics

, Volume 2, Issue 11, pp 329–334 | Cite as

Fatigue and static strength of notched and unnotched aluminum-alloy and steel specimens

Principal objective of paper is to present data on some commonly used aircraft materials in a form so that variations in the fatigue strength with elastic stress-concentration factor can be shown
  • Richard E. Whaley
Article

Abstract

This paper describes a method of presentation of fatigue data on three commonly used aircraft materials, 2024-T3 and 7075-T6 aluminum alloys and normalized SAE 4130 steel, such that variations in fatigue strength with stress-concentration factor can be shown. Comparisons of the fatigue strengths of 2024-T3 and 7075-T6 aluminum are made for the most useful range of stress-concentration factors.

Static-strength results of notched and unnotched specimens of the three materials are presented to show how the strength varies with some parameters of the stress concentration. Comparison of the data with one theory for the strength of cracked specimens was made.

Keywords

Aluminum Fatigue Mechanical Engineer Aluminum Alloy Fluid Dynamics 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Symbols

A

Neuber material constant, in

Kf

fatigue-strength-reduction factor

Kn

Neuber “practical” stress-concentration factor

Kt

elastic stress-concentration factor

Ku

theoretical stress-concentration factor for ulti mate tensile strength

r

notch-root radius, in

Smax

maximum load divided by initial net sectional area, ksi

So

ultimate tensile strength of unnotched specimen, ksi

Su

ultimate tensile strength of notched specimens, ksi

NSR

Su/So=notch strength ratio

q

notch sensitivity

γ

relative stress gradient, in.−1

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References

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  2. 2.
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  3. 3.
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Copyright information

© Society for Experimental Mechanics, Inc. 1962

Authors and Affiliations

  • Richard E. Whaley
    • 1
  1. 1.McDonnell Aircraft Corp.St. Louis

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