Effect of the residual fatigue damage on the static and toughness properties

Abstract

This investigation has been carried out in order to study the influence of the residual fatigue damage on the tensile and fracture toughness properties of a 6082-T6 aluminum alloy during high cycle fatigue. The results obtained show that the tensile mechanical properties do not change with the amount of residual fatigue damage. The mechanical properties remained unchanged because in high cycle fatigue, the magnitude of plastic strain was smaller than for low cycle fatigue. However, the fracture toughness results have shown that the critical crack opening displacement CODc decreases in the range of 10-40% and the critical energetic parameter J1C decreases in the range of 20-25% with fractional lifetime n/Nf for the maximum stresses applied of 200 and 275 MPa respectively. This decrease of the toughness parameters could be attributed to microcracks evolution during high cycle fatigue. © Springer Science + Business Media B.V. 2009.