A fracture mechanics based approach to predict fatigue life of scratch damaged shot peened components

✍ Scribed by R.A. Cláudio; J.M. Silva; C.M. Branco; J. Byrne

• Publisher: Elsevier
• Year: 2011
• Tongue: English
• Weight: 352 KB
• Volume: 10
• Category: Article
• ISSN: 1877-7058
• DOI: 10.1016/j.proeng.2011.04.445

✦ Synopsis

Shot peening is a surface treatment widely used in industry in order to extend service life of a large number of components. Recent experimental studies demonstrated that if a scratch of certain size is created over the shot peened surface then the benefit can be reduced or even completely eliminated. Almost no work was published regarding modelling or predicting the fatigue behaviour of the scratch damage over shot peening. This work presents a methodology to predict the fatigue life and non-propagating cracks of scratch damaged shot peened components. The finite element method was used to determine the actual strain at surface and facture mechanics parameters calculated from cracks emerged on the residual stress profile. The total fatigue life is obtained by adding initiation life, which is calculated by the strain-life model, with crack propagation life determined using da/dN curves. A good agreement was found between the numerical predictions and experimental results, showing that this method is quite reliable for predicting both fatigue life and non-propagating cracks of scratch damaged shot peened components.