Accession Number : ADP001611

Title :   Spectrum Effects on the Growth of Short Cracks,

Corporate Author : WISCONSIN UNIV-MADISON

Personal Author(s) : Sandor,B. I. ; Haas,D. A. ; Ozakat,T.

Report Date : APR 1983

Pagination or Media Count : 7

Abstract : Several phenomena are discussed concerning creep-fatigue effects on crack initiation and propagation in notched 7075-T651 aluminum at room temperature. Background data show complete creep ruptures of smooth specimens in a time of 10 to the 6th power at stresses about equal to the yield strength. Creep rate under a constant load decreases in the first half of the life and increases in the second half. In notched specimens (Kt = 4) tensile overloads with hold times result in additional extensions of the fatigue life beyond that of brief overloads.

Descriptors :   *Airframes, *Cracking(Fracturing), *Structural mechanics, Crack propagation, Sizes(Dimensions), Growth(General), Fatigue(Mechanics), Creep, Loads(Forces)

Distribution Statement : APPROVED FOR PUBLIC RELEASE