Transition from progressive to global buckling of aluminium extrusions – a numerical study

Abstract

Numerical simulations using LS-DYNA were carried out in order to study the transition between progressive and global buckling of axially loaded aluminium extrusions in alloy AA6060 temper T6. A numerical model was validated against experimental tests and good agreement was found between the progressive buckling pattern in the numerical simulations and experimental tests. The numerical simulations were capable of giving a relatively accurate prediction of the collapse mode found in the experimental tests. The critical global slenderness is defined as the global slenderness, or length to width ratio (L/b), where direct global buckling or a transition from progressive to global buckling occurs. The validated numerical model was used in a parametric study where the influence on the critical global slenderness from impact velocity and material properties has been studied. The means to stabilize the response and increase the critical global slenderness has been investigated. It was found that the introduction of a heat affected zone at the impacted end increased the critical buckling length.