The Forming Limit Curve (FLC) and its Application in the Analysis and Simulation of Stamping Processes

Abstract

The Forming Limit Curve (FLC) is a primary tool for evaluating sheet metal formability. This article reviews its fundamentals and the classic experimental methods for obtaining it, such as the Nakazima and Marciniak tests, discussing their advantages and limitations. The application of FLC in stamping simulation software, such as AutoForm, is also presented, highlighting its importance for predicting failures, optimizing process parameters, and reducing development costs. Finally, the limitations of traditional FLC, which is highly dependent on the deformation path, are discussed, as well as recent advances in FLC based on equivalent plastic deformation (ep-FLC), which improves accuracy in nonlinear forming paths.