Instability predictions are important in sheet-metal forming processes
, one such instability being splitting failures due to localized necki
ng. The majority of such sheet-metal industrial splitting failures occ
ur near to the plane-strain state. Therefore, sheet-metal industries h
ave always been looking for an ''ideal'' formability test which allows
them to evaluate sheets for their ability to resist splitting failure
s under near plane-strain conditions. Several formability tests have b
een developed in the past but none have been very successful. Presentl
y, a new test has been designed, constructed and used to evaluate the
formability of different sheet materials. The results from this new te
st are compared with standard limiting-dome-height (LDH) tests and fin
ite-element simulations. The results show that the new test is more re
producible, more closely follows the desirable plane strain path and t
akes roughly 1/6 of the time to perform relative to the LDH test. Stra
in measurements and finite-element simulations have revealed that the
improvements are a result of the new test geometry, which produces a m
ore stable and repeatable plane-strain state near to the splitting fai
lure locations. The failure heights in the new tests were predicted us
ing a section analysis finite-element program, SHEET-S.