Analytical modelling for residual stresses produced by shot peening

In the present work, an analytical model for the residual stresses formed during the shot peening process is analysed. The model employed was proposed by Li and co-workers [Li J et al. Mechanical approach to the residual stress field induced by shot peening. Mater Sci Eng 1991;A147:167–73] and complemented by Shen and co-workers [Shen S et al. Assessment, development and validation of computational fracture mechanics methodologies and tools for shot-peened materials used in rotorcraft principal structural elements [S.I.], 2004]. However, two modifications are adopted: the hertzian pressure is considered as a dynamic load and the Ramberg-Osgood and/or Ludwick constitutive models of the stress–strain curve is adopted to describe the plastic behaviour of the target material. The resulting model is checked using experimental measurements obtained in the literature of residual stresses on a 4140 steel shot peened target as well as on our own data for shot peened Al 7475 alloy.