Modeling of shot peen forming using non-Euclidean plate theory*

Shot peen forming is a versatile technique for shaping large thin panels by impacting them with thousands of high-velocity millimeter-sized shots. The process is widely used in aerospace, notably to form wing skins. Two main factors hinder the process’ efficiency: the lack of accurate and simple modeling tools and the lack of automation. Without modeling, the process’ setup relies on a lengthy trial and error procedure. Our project is intended to fill this gap and to provide the industry with a reliable and efficient modeling software. The software is based on innovative theoretical framework of non-Euclidean plate theory relying on Riemannian geometry. This theory was initially developed to describe growth-induced reconfiguration of thin organic tissues, and in terms of mechanics these processes share many similarities with peen forming. It is the incompatibility between local stretching and curvature induced by different mechanical processes that is viewed as the reason of reconfiguration. The accuracy and performance of our software were examined in laboratory conditions by comparing simulations with experimental results for the case of large 1x1m aluminum plates submitted to peen forming.