A Study of the Effects of Repeated Tension Impact Loads Upon Certain Metals Used in Aircraft Construction

Authors: Olsen, Carl Baker; Brown, Sheldon Willis

Year: 1942

Degree: Engineer's thesis

Advisor: Sechler, Ernest Edwin

Committee Member: Unknown, Unknown

Option: Aeronautics

DOI: 10.7907/RXJQ-C567

Abstract

The repeated tension impact properties of a manganese bronze, used in aircraft landing gear fittings, are presented in this report.

The repeated tension impact test apparatus was adapted to take specimens in the form of sheet as well as specimens of the conventional bar type. With the modified apparatus, data on Alcoa 24 S-T and Dowmetal J-1H sheet specimens of varying thicknesses were obtained in order to present the aircraft designer with information directly applicable to the sheet materials currently in use.

An investigation was made of the effect of service operation on the repeated tension impact properties of three 25 S-T propeller blades. For this purpose, propeller blades were used with approximately 5,314, and 788 hours of service operation.

A new machine, specifically designed for repeated tension impact testing, was placed in commission. With this machine, repeated tension impact test data on 24 S-T bar stock were extended to higher velocity ranges in an effort to determine the effect of velocity of impact.

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