Shot Peening Process Modelling on Gas Turbine Applications

Author:  Pierangelo Duó, Hendrik Andresen
Source:  ICSP-13
Doc ID:  2017099
Year of Publication:  2017
Abstract:  
Abstract: The application of surface treatments to finished parts in gas turbine aero-engines such as shot peening is one of the most common procedures to prevent early fatigue crack initiation and propagation to enhance the resistance against environmental induced corrosion fatigue, stress corrosion, wear generation, and fretting. Whilst much was done in recent years to develop numerical approaches which could reproduce the effects of the shot peening process [Ref. 1], a historical and mainly empirical approach, based on generated knowledge and experience to define the parameters for the same process applicability, is still widely used in the industry. Objective of the current work is to introduce, define and develop a numerical approach which would allow to replicate the real process and to predict the effects of shot peening. A set of numerical tools, for given shot peening input parameters and nozzle geometry, is here developed and the gained knowledge is then applied to representative 3D features on gas turbine components. Firstly is introduced the usage of equivalences between the experimental based and the numerical work for the shot peening process, focusing on the definition of conventional fundamental parameters such as intensity and coverage, which are then used in the numerical Finite Element (FE) simulations. Details are given to demonstrate the method has a validation basis to be trusted for a simple but representative geometry, i.e. a flat specimen. The definition introduced is validated over a simplified but still numerically representative form, the so called symmetry cell. The numerical tools applied are time-dependent numerical FE methods, with a selection of adequate material models. The methods developed are then selectively applied to representative geometry 3D features, with a selective example reproduced in details.