Effect of shot peening on the fatigue life and crack propagation prediction with experiments and Navarro-Rios Model

Author:  H.Y. Miao and M. L
Source:  Conf Proc 2011: ICSP-11 South Bend, IN USA (pgs. 7-11)
Doc ID:  2011001
Year of Publication:  2011
Abstract:  
Abstract Shot peening induces compressive residual stress in the top layer of a treated component. These stresses retard crack initiation and crack propagation. However, shot peening increases surface roughness which acts as stress concentrator and accelerates crack initiation. Therefore, the effect of shot peening depends on the balance of this beneficial effect (compressive residual stress) and detrimental effect (surface roughness). In this paper, a Navarro-Rios model has been developed based on the studies of De los Rios et al. [1] and Curits et al [2]. With this model, it is possible to study the propagation of the short crack of the peened component considering the residual stress and surface roughness after different peening intensities (0A, 2A, 4A, 6A, 8A and 10A). The predicted fatigue life limits are consistent with the experimental results from Michaud [3], especially for peened components under larger applied stress. In this studied case, both experimental and theoretical results show that peening intensity 2A produces best fatigue life improvement due to appropriate compressive residual stress and surface roughness. Keywords Shot peening, Almen intensity, fatigue life, crack propagation, Navarro-Rios model.