Multi-objective Optimization of Shot-peening Parameters using Design of Experiments and Finite Element Simulation: A Statistical Model

Shot-peening is a mechanical surface treatment used extensively in the industry to enhance the performance of metal parts against fatigue. Thus, it is important to determine main parameters of shot-peening in order to obtain its optimal values. The purpose of this study is to achieve a statistical model to determine the important parameters of the shot-peening process by considering the effect of sample thickness on the responses and achieving the multi-objective optimal parameters. To do this, response surface methodology are used to determine the governing models between the response variable and the input parameters. Shot velocity, shot diameter, coverage percentage and sample thickness are selected as shot-peening parameters. Residual compressive stress, its depth and roughness are considered as the response variable. Using finite element analysis, shotpeening process are simulated. The desirability function approach is used for multi-objective optimization so that the optimal shotpeening parameters, which simultaneously provide two response variables in optimal mode, are obtained. The results show that surface stress and maximum residual stress are independent of shot velocity, whereas, the depth of the compressible stress and roughness are directly related to shot velocity. In addition, thickness modifies surface stress and the depth of the compressible stress. The optimal conditions for surface stress, maximum compressive stress, and roughness simultaneously with high-coverage and low-velocity can be achieved as well.