Accession Number : ADA019496

Title :   The Influence of Cyclic Loading on Residual Stress Relaxation.

Descriptive Note : Master's thesis,

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

Personal Author(s) : Burski,Michael L.

Report Date : DEC 1975

Pagination or Media Count : 58

Abstract : The study was experimental determination of the existence of residual stress relaxation in 7075 T651 aluminum under constant amplitude cyclic loading. A unique three bar coupon was designed so that the two outer members remain totally elastic while the middle member is allowed to plastically deform. Stress determination of the plastic member is possible using only data from the other two members. An MTS machine was used to load the coupon so that a residual stress existed on the middle member while the other members remained totally elastic. A cyclic load of constant amplitude was then applied to the coupon. It was found that the stresses in the totally elastic members did not change at all during the cyclic loading. Thus relaxation of the residual stress in the middle member did not occur, as various fatigue theories have assumed it would.

Descriptors :   *Stress relaxation, *Aluminum alloys, Residual stress, Cyclic tests, Loads(Forces), Creep, Fatigue(Mechanics), Theses

Subject Categories : Metallurgy and Metallography
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE