Study on fatigue crack growth property of abrasive waterjet peened aluminum alloy

Abstract

Abrasive waterjet peening is a favorable surface treatment method for improving the fatigue resistance of metal materials. An insight into the fatigue crack growth properties of AWJ peened specimens is meaningful for obtaining better strengthening performance. In present work, a numerical model of AWJ peening was established and experimentally validated for investigating the fatigue crack growth characteristics of Aluminum specimens. The effect of peening and loading conditions on the fatigue performance was also analyzed. The results indicated that the stress intensity factor at the peened region was enhanced and the crack propagation was significantly inhibited by the compressive residual stress. The influence of compressive residual stress on the effective stress factor range is greater under lower external load and higher loading ratio. The fatigue life for reaching the crack length of 40 mm is increased by 37%, 60% and 98% after peening by using the intensity of 0.6 mmA, 0.8 mmA and 1 mmA, respectively.

Keywords

• fatigue crack
• AWJ peening
• stress intensity factor
• crack growth rate