3D in situ study of damage during a ‘shear to tension’ load path change in an aluminium alloy

A load path change (LPC) from shear to tension has been studied for a recrystallized 2198 T8 aluminium alloy sheet material by three-dimensional (3D) X-ray imaging combined with image correlation and interpreted complementary 3D finite element (FE) simulations. cross-shaped specimen was designed the non-proportional loading multiscale study. The effect of LPC on formability related strain localisation, damage failure investigated mechanisms could be clearly identified. macroscopic stretch fracture, measured an optical extensometer during test, reduced about 20% compared proportional test. Damage, in situ laminography at ?m-scale resolution, interestingly already found under shear, quantified as surface void fraction LPC. Strain inside mesoscale 2D digital (DIC) projected volume data, using (natural) intermetallic particle contrast present laminographic data. An accumulated equivalent definition, suited description loading, applied DIC data FE simulations, indicating good agreement between both. On microscopic scale, seen nucleate form flat cracks, similar width grain size, cracks particles. This subsequently grew coalesced tensile which turn led final fracture.