Application of indentation as a retardation mechanism for fatigue crack growth

The aim of this study was to evaluate the influence of a mechanical impact applied in front of a crack tip on fatigue crack growth retardation. Many experiments and numerical simulations were conducted, and the methodology for the numerical evaluation of impact efficiency on fatigue life is stated. Data evaluation and analyses confirmed the expected crack growth retardation and lifetime enhancement. The impact energy, crack length and load level had a substantial effect on the retardation of crack growth. Under suitable conditions, the impact indentation technique can cause the full arrest of crack propagation. The efficiency of impact application as a crack stopper increased mainly because of the reduction in the stress intensity factor values. In some cases, this method can replace more conventional approaches, such as drilling or repair by bonded or mechanically joined patches.

► We propose the indentation technique for fatigue crack growth retardation.
► Both experimental and numerical study to verify this phenomenon is presented.
► Dynamic punch hit with a predefined impact energy is applied in front of a crack tip.
► The impact energy has a substantial effect on the retardation of crack growth.