Numerical analysis for effects of shot peening on fatigue crack growth

In the present work numerical analysis for effects of shot peening on fatigue crack growth are reported and discussed. Simulations reported in the present work use irreversible cohesive zone model and are based on experimental data for a Nickel-based superalloy. The capability of the cohesive zone model to catch the effects of short crack is investigated. The two-dimensional computations fit known experimental records in the CT specimen which confirms that the cohesive zone model has the potential for engineering application. The fatigue crack growth of shot-peened specimens are studied for different loading amplitudes and different shot peening intensities. The numerical results reveal that the crack initiation position and time depend not only on the shot peening intensity but also on the cyclic loading amplitude. Retardation of fatigue crack growth is more effective at lower loading amplitude for shot-peened specimens, and higher applied loading will eliminate the beneficial effects of shot peening.

► Paris-like behavior of crack growth can be simulated by cohesive zone model.
► Short crack effect can be captured by cohesive zone model.
► Crack can initiate from the position beneath the initial crack for peened material.
► Higher applied load will eliminate the beneficial effects of shot peening.