Formation of shot dimples during shot peening

Abstract

In the aircraft industry, the technology of shot peen treatment is successfully used for the manufacture of long panels and sheaths, both for forming and finishing hardening. Shot dimples increase the roughness of the treated surface, so after the shot peening, the surface should be grinded with flap wheels to improve the roughness values by partially removing the traces of shot impact. To assess the quality of shot peening as a monitoring indicator, in practice the degree of coverage of shot dimples on the treated surface is used, which is determined by the percentages of the total area of shot dimples to the total area of the considered treatment part. To assign the modes of subsequent grinding with flap wheels, it is necessary to determine the allowance for grinding, which is determined by the value of the maximum depth of the largest dimple within the base area of the treated surface. The paper presents a method of creating a mathematical model to determine the size of dimples in shot peening, as well as modeling and engineering analysis of the shot peening process with the finite element method.