Measurement of anisotropy in deformation and fracture strength of aluminum beverage can using biaxial stress tests

Anisotropy in deformation and fracture strength of an aluminum beverage can body is investigated using a servo-controlled tension-internal pressure testing machine. The yield surface and forming limit strain and stress diagrams of the can body are successfully determined using linear strain-path tests. We conclude as follows:(i)The initial yield surface of the can body is in good agreement with Yld2000-2d yield criterion with degree of 10;(ii)fracture always occurs at θ=0° under linear strain-paths with eθ/eφ>1, where θ is the circumferential position on the can body measured from the rolling direction of the blank sheet, and eθ and eφ are circumferential and axial strain components, respectively. We found that eθ is significantly lower at θ=45° than at θ=0° and 90°;(iii)The fracture strength of the can body under plane-strain tension with eφ=0 is minimum at θ=0°and maximum at θ=45°; this accords with the result of(ii);(iv)In order to evaluate the fracture strength of the can body accurately, the stress state of the can body in the test should be as close as possible to the one that occurs in a can body in a real service condition.