Effect of ring indentation on fatigue crack growth in an aluminum plate

In the present investigation, a more efficient method for retardation of fatigue crack growth is examined. Residual stresses were created around the crack tip by indenting a cracked panel with rigid ring punches. The residual stresses near the crack tip were evaluated using fracture mechanics principles with the Bueckner weight function. It was observed that a state of compressive residual stress is introduced inside the indentation area. Fatigue testing of an aluminum specimen with single edge crack showed that the significant retardation effects were observed after the application of the ring indentation. It is also shown that the ringindentation process increases the total fatigue life.