Accession Number : AD0663920

Title :   EFFECT OF VACUUM ON THE STRENGTH OF BALSA WOOD.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OHIO SCHOOL OF ENGINEERING

Personal Author(s) : Blair,F. E. ; Johnson,S. W. ; Torvik,P. J.

Report Date : 1967

Pagination or Media Count : 30

Abstract : Previous investigations have shown that exposure to vacuum has little effect on the ability of balsa wood to absorb energy. Because this material has, in addition to its energy absorbing capability, a favorable strength to weight ratio and can be cut and shaped with ease, the use of balsa wood as load carrying members in space is a distinct possibility. In this investigation, specimens of oven-dry balsa were loaded to failure in either bending or compression after exposure to vacuums of 0.0001 to 0.00001 torr for periods as long as twelve days. Some specimens exposed to vacuum were tested in vacuum; others were tested in air. As controls, the strength properties of similar specimens which had not been subjected to vacuum were determined. The effect of vacuum on compressive and bending strengths was found to be negligible. A small weight reduction primarily due to a loss of mositure while in vacuum was observed, but no damage to the cellular structure of the wood was detected when thin sections of exposed and unexposed wood were examined and compared under a microscope. (Author)

Descriptors :   (*WOOD, *VACUUM), MECHANICAL PROPERTIES, LOADS(FORCES), FAILURE(MECHANICS), COMPRESSIVE PROPERTIES, BENDING, MICROSTRUCTURE, SPACE ENVIRONMENTS

Subject Categories : Wood, Paper and Related Forestry Products

Distribution Statement : APPROVED FOR PUBLIC RELEASE