Author(s)

M.A. Fonte & M.M. de Freitas

Abstract

An analysis of the influence of steady torsion loading on fatigue crack growth of semi-elliptical cracks under rotating and reversed bending is presented. The crack growth has been studied in two different fatigue machines which perform mixed mode (i+m) loading obtained by cyclic mode I (AKj) with superimposed static mode III (%J loading. Tests were carried out on cylindrical specimens in Ck45k steel and the results are compared in both loading conditions: rotating and reversed bending with and without steady torsion. Results show that the static mode III loading superimposed to mode I leads to a significant reduction on the crack growth rates. The influence of these phenomena could be related with an increased "crack closure effect" associated

Keywords