An experimental and numerical investigation of the static and dynamic constitutive behaviour of aluminium alloys

摘要

A split Hopkinson pressure bar (SHPB) set-up was used to investigate the dynamic constitutive behaviour of commercial aluminium alloys both experimentally and numerically. The study was conducted in a 500-10 000 s~(-1) strain rate regime. Both regular solid and modified hollow transmission bars were employed in realizing this strain rate regime. Four different aluminium alloys, namely 7075-T4, 2024-T3, 6061-T6, and 5182-0, were considered for investigation. A copper-110 alloy pulse shaper was used to obtain better force equilibrium conditions at the bar-specimen interfaces. A plastic kinematic model was used to model the rate-dependent behaviour of aluminium alloys using commercially available ANSYS LS-DYNA software. Compared with the quasi-static condition, all four alloys showed a slight rate dependency with an increased flow stress ranging from 50 to 100 MPa at much higher strain rates. It was established from the final results that the experimentally determined dynamic constitutive behaviour matches very well with the numerical value in a 2000-5000 s~(-1) strain rate regime.