Numerical Prediction of Fracture and Perforation Behaviours of Recycled Aluminium Alloy AA6061 Using Taylor Cylinder Impact and Perforation Tests

Abstract

Directly recycled AA6061, valued for its energy-efficient production and reduced environmental impact compared to primary aluminium, exhibits unique mechanical properties due to microstructural changes during recycling. Behavioural analysis under various loading conditions, including tensile and impact tests, reveals mild ductility and anisotropic deformation patterns such as petal formation, plugging, and fragmentation. This study investigates the fracture and perforation behaviour of AA6061 plates under high-velocity impacts using a numerical model based on the Johnson-Cook material and failure models. Simulations of Taylor cylinder impact tests, conducted at velocities ranging from 280 m/s to 370 m/s, show strong agreement with experimental data, validating the Simplified Johnson-Cook model’s effectiveness in predicting fracture behaviour under impact loading. Building on these results, the study explores the Johnson-Cook Failure Model in perforation tests with severely fractured specimens. Simulations accurately predict perforation behaviour at lower impact velocities and smaller bullet diameters, particularly in cases of limited deformation. However, at higher velocities and larger bullet diameters, prediction accuracy decreases due to complex fracture patterns and asymmetric deformations. The study concludes that while the current failure model provides a foundational understanding of fracture and perforation behaviour in recycled AA6061, further refinements are necessary. Enhancing the failure model, specifically for recycled aluminium, could improve its predictive accuracy across a broader range of impact scenarios, addressing the limitations observed in cases of severe deformation and complex fracture mechanisms.