Dynamic simulation of a peen forming jet blast

Ricardo Augusto de Barros Leite¹; Flavius Portella Ribas Martins²; Agenor de Toledo Fleury³

¹ Eniversidade de São Paulo; ² Universidade de São Paulo; ³ Centro Universitário da Fundação de Ensino Inaciano

doi:10.20906/CPS/COB-2015-0443

Resumo

Peen forming is a plastic cold work process of shaping a metallic sheet or panel through the impact of a regulated blast of small round steel shots on its surface, in order to produce a previously desired curvature. The application of the shot peening as a forming process has been a well known technique in the industry for the last decades, but even in the recent years a good amount of research has been done in order to improve it. Peen forming process planning requires the measurement and control of several variables concerning the dynamics of the shot jet and its interaction with the piece to be shaped, As previously shown by several authors, impact velocity is one of the variables that most contribute to the development of the residual stress field that causes the material to bend. In this article we present a simplified dynamical model describing the motion of a large number of small spheres (shot) impelled by a steady air flow and suffering multiple collisions with each other and with the part to be shaped. Computer simulations of this model permitted to identify correlations between the shot field velocity and the parameters of the process, a first step to furtherly design controlled systems for peen forming machines.

Palavras-chave: peen forming; shot peening; process planning; two-phase flows