Author(s)

R. Cook & P. Holdway

Abstract

Residual stresses induced by hole cold expansion R. Cook, P. Holdway Materials and Structures Department, Defence Research Agency, Farnborough, Hampshire, UK ABSTRACT This paper describes an X-ray diffraction technique for measuring residual stresses. The results of measurements at locations in the vicinity of plain and cold expanded holes in an aluminium alloy are presented. Residual stresses are shown to vary significantly in all three dimensions and two dimensional analyses commonly used for residual stress determination are shown to be inadequate. The results of a fatigue test programme are also presented in which simple aluminium alloy specimens containing plain and cold expanded holes were subjected to constant amplitude fatigue loading. The results show that cracks from plain holes continuously increase in growth rate to failure whilst cracks from cold expanded holes decrease in growth rate and frequently arrest. The arrested crack

Keywords