Numerical analysis for the influence of casting micro porosity on fatigue life

• A numerical life prediction approach accounting for micro porosity was proposed.
• Representative volume element and theory of critical distances were combined.
• Fatigue analysis without considering micro porosity would make an overestimation.
• With the increase of porosity volume fraction, the fatigue life decreased sharply.
• Good accuracy of life prediction taking into account of porosity was obtained.

The quantitative influence of casting micro porosity on fatigue life still remains unclear. In the study, by combining the representative volume element method and theory of critical distances, a numerical analysis approach for investigating micro porosity’s effect on fatigue life of casting materials has been established. Taking as an example, the fatigue life of an A319 alloy with varying porosity volume fractions were predicted. The results indicated that the proposed life prediction approach was capable of accurately reflecting the decrease of fatigue resistance due to the increasing micro porosity volume fraction.