PNNL

Abstract

The formability of aluminum alloy AA5182-O and DP600 steel sheets at high-strain-rates was investigated using an electrohydraulic forming (EHF) setup. Test sheets, ~150 mm diameter x 1 mm thick, were clamped around their circumference and subjected to a pressure-pulse (several 100 ?s duration) generated by a high-energy (up to ~34 kJ) under-water electrical discharge. The real-time strain and strain-rate of the deforming sheets were quantified by the digital image correlation (DIC) technique using a pair of high-speed cameras (~15 ?s per frame). Strain-rate amplification was observed when the sheets were deformed into a conical die, with the maximum in-plane strain-rate and strain for aluminum measured as ~1200 /s and ~0.2, respectively. The deformation behavior of the sheets was modeled using ABAQUS/finite element explicit code and better correlation, between the predicted and the experimental sheet deformation behavior, was observed when an alternate pressure-profile was used instead of the one available from the literature.