Energy Absorption of Channel Beams during Gross Deformation

The results of experiments to determine the energy absorbed by aluminium alloy channel sections when loaded with combined compression and bending causing gross deformation, plasticity and fracture are described.

The lateral-torsional mode of buckling caused a radical redistribution of stress leading to large tensile strains developing in the initially compressed flange. Provided the material is able to flow, the energy absorbed showed a smooth monotonic increase with increasing deformation, therefore suitable for crashworthy structures.

A predictive method is outlined based on a coarse finite element division used in a non-linear orogram accounting for the finite rotations and plasticity.