Improved lifetime estimation of shot-peened shaft bores using a numerical approach

Shot peening is commonly used to improve the fatigue strength of mechanical components. The peening process involves the use of high-energy mechanical impacts to create compressive residual stresses and a material hardening on the surface of the component, which can significantly increase its resistance to fatigue. Accurate lifetime prediction is important for optimizing the design of shot-peened components and ensuring their reliability and safety. Due to nonlinear material behavior and the simulation of contact, estimating the lifetime of shot-peened shaft bores under cyclic loading conditions remains a challenge. In this study, the lifetime estimation of shot-peened shaft bores using a combination of experimental testing and finite element analysis is investigated. A series of experiments was conducted on shot-peened shaft bores made of EN-GJS-700 and 34CrNiMo6, using different peening parameters such as intensity and coverage. The specimens with shot-peened shaft bores were subjected to cyclic loading in a fatigue testing machine and the lifetime was experimentally identified. The results were used to develop a methodology based on finite element analysis, which considers the effect of the shot peening parameters on the residual stress distribution, hardening and the resulting fatigue life. The results of the proposed methodology were validated against the experimental data and showed good agreement with the experimental results. The derived methodology can be used to estimate the lifetime of shot-peened shaft bores under different loading and peening conditions and provides a useful tool for optimizing the design of shot-peened components in fatigue engineering applications.