Fatigue Stress Concentration Studies on Aluminum Alloys

Author: Dervishyan, Aram Ohannes

Year: 1952

Degree: Engineer's thesis

Advisors: Sechler, Ernest Edwin; Hudson, Donald E.; Williams, Max L.

Committee Member: Unknown, Unknown

Option: Aeronautics

DOI: 10.7907/4BCE-M652

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document.

Fatigue tests in reversed bending were conducted in 75S-T6 and 17S-T6 aluminum alloys to determine whether Neuber's theory on fatigue stress concentration factors in notches was applicable to these materials. The results of the tests indicate confirmation of the theory within engineering accuracy providing the value of […] (a material constant) is determined experimentally.

Material size effect was investigated and found to exist. This was an unexpected result since other sources (see References 3 and 4) indicated that no size effect existed for aluminum alloys.

Ignoring the correction due to size effect a value of the Neuber's constant […] of approximately 0.05" gave reasonable checks with the experimental data for both 75S-T6 and 17S-T6 aluminum alloys. This may indicate that this value of […] is the correct material constant for aluminum alloys but additional data on other alloys is needed to confirm this conclusion.

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