Experimental studies on the quasi-static axial crushing of steel columns filled with aluminium foam

Experimental investigations are carried out in order to study the effects of different tube and filler arrangements on the crushing behaviour of axially compressed tubular crush elements. To this end quasistatic experiments are performed on monotubal and bitubal, empty and filled steel profiles with different materials, dimensions and cross-sectional shapes. Aluminium foam, produced by a powder metallurgical production process, is applied as filler material. The test results confirm that considerable mass efficiency improvements with respect to energy absorption may be obtained, even if reduced stroke lengths, caused by the presence of foam, are taken into account. Distinct differences are pointed out between the different cross-sectional shapes. Bitubal arrangements, consisting of outer and inner profiles with foam in between, are shown to be particularly efficient crush elements, as long as global failure can be avoided, Explanations for the experimental observations are obtained by a simplified analysis of interaction effects, Constraints concerning the appropriate choice of Al-foam densities are summarized, too, in order to provide an aid for the future design of 'optimally tuned' crush elements composed of tubular members and Al-foam. (C) 2000 Elsevier Science Ltd. All rights reserved.