Critical evaluation of the formability of AA2024-T3 sheet deformed by single-point incremental forming

Abstract

The evaluation of the enhanced formability in incremental

sheet forming processes (ISF), and especially in its simplest

variant single point incremental forming (SPIF), has been

intensively studied within the sheet metal forming community

for the last decade. In general, the formability limit in SPIF is

defined by means of the fracture forming limit (FFL). This FFL

is usually well above the forming limit curve (FLC), which is

the limit controlling failure by necking in conventional sheet

metal forming operation on ductile metal sheet. However, low

ductility sheet metal such as AA2024-T3 presents usually a

fracture-controlled mechanism independent to the forming

operation considered. In this context, this paper consist in

a critical analysis on formability and failure of AA2024-T3

sheets deformed by SPIF. The study is carried out from a

double perspective based on an experimental plan including

conventional and incremental forming tests, and numerical

simulations using the flow formulation finite element tool

DEFORM-3D®. The results show the experimental evidence of

a formability enhancement in SPIF above the conventional FFL

for this kind of material as well as the necessity of calibrating

numerical simulations of these incremental forming processes

using experimental data obtained from the corresponding

experimental SPIF tests.