Accession Number : AD0760668

Title :   Effect of Mean Stress Intensity on Fatigue Crack Growth in a 5456-H117 Aluminum Alloy.

Descriptive Note : Research and development rept.,

Corporate Author : NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER ANNAPOLIS MD

Personal Author(s) : Chu,H. P.

Report Date : JUN 1973

Pagination or Media Count : 43

Abstract : Fatigue crack growth data on a 5456-H117 aluminum alloy was obtained by testing compact tension and contoured double cantilever beam specimens. The effect of tensile mean stress on crack growth rate is found to reach a maximum when stress ratio R > or = 0.25. The crack propagation laws are discussed, and two new equations are developed. It is shown that the new equations can represent the entire range of fatigue crack growth rate, versus applied stress intensity for different R values from threshold behavior to unstable fracture. (Modified author abstract)

Descriptors :   (*ALUMINUM ALLOYS, *CRACK PROPAGATION), FATIGUE(MECHANICS), STRESSES, FRACTURE(MECHANICS)

Subject Categories : Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE