Analysis of deformation history and damage initiation for 6082-T6 aluminium alloy loaded at classic and symmetric Taylor impact test conditions

• Axial damages during RoR Taylor test are effect of high-stress triaxiality peaks.
• Impact conditions in RoR test are equal to those of impact into perfect rigid body.
• Deflection of anvil during RoA test reduces peaks value, damage is prohibited.
• Crack on the perimeter are effect of stable increase of specimen foot diameter.
• No influence of impact velocity on the stress triaxiality course in RoA test.

Taylor impact tests in the classic and symmetric configurations were applied to analyse the development of plastic deformation and damage in Al-6082-T6 rods. Deformation histories during impact were recorded using high-speed photography, while internal axial damage was identified using metallography. The axial damage observed during the symmetric test were initiated during stress triaxiality peaks under tensile loading conditions. Variations of the stress state are the result of superimposed lateral mechanical waves reflected from the perimeter of the specimen. The fracture strain decreases with the increase of the stress triaxiality; it is thus possible to initiate damage at relatively low strain values under high-stress triaxiality values. During classic Taylor test because of the deflection of the elastic steel anvil in the rod on anvil test, the oscillations are smaller and quickly damped in comparison to the rod on rod experiment. Therefore, the initiation of axial damage is impossible. The cracks on the specimen edge are due to tensile loadings. For both the symmetric and classic Taylor tests, the damage conditions are comparable, i.e., a stable increase of strain combined with tensile loadings.