Column Creep of 75S-T6 Aluminum Alloy

Author: Gaibler, Richard

Year: 1952

Degree: Engineer's thesis

Advisor: Sechler, Ernest Edwin

Committee Member: Unknown, Unknown

Option: Aeronautics

DOI: 10.7907/DTB9-Y232

Abstract

This thesis is a report of the results of the column phase of a three part experimental investigation of short time creep properties of light metal alloys under conditions of high loadings and elevated temperatures. The other parts of the investigation were concerned with creep properties of these alloys in tension and in compression. The former is described by R. J. Kauffman; the latter by R. C. Thatcher (Refs. 11 and 12).

Creep characteristics of 75S-T6 aluminum alloy columns having various effective slenderness ratios were investigated at 450°F and 550°F. Of primary interest was the region of applied stresses near the maximum stresses which these columns would sustain. Lateral creep deflection of the column midpoint was measured. Coincident with this measurement, time to failure of the column was also measured. Columns tested at 550°F had rectangular cross sections and had effective slenderness ratios of 25.5, 39.9, 48.6 and 57.2. Columns tested at 450°F. had rectangular cross sections and had effective slenderness ratios of 25.5, 48.6 and 57.2.

Testing equipment was designed and constructed for the investigation. A constant load was applied to the specimen by means of a lever arm having a ten to one mechanical advantage. The specimen was heated in an electric oven. The oven was maintained at temperature by automatic electrical control.

It was found that 75S-T6 aluminum alloy columns having effective slenderness ratios of 25.5 to 57.2 are suitable for short time (0 - 10 min.) use at 450°F and 550°F.

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