Development and Characterization of a Composite Cylindrical Column with an Aluminum Foam Core

Cellular materials in general and metal foams in particular are becoming more accessible to the automotive industry as technologies get further developed and the supply chain expands. Among the recognized properties of metal foams are high plastic deformation energy and light weight, which is a combination that could be leveraged advantageously in impact and crash applications. In this study, cylindrical shells with aluminum foam cores were crushed in the longitudinal direction, an embodiment that approximates those found in vehicle crumple zones and roof pillars. The cores were made of Duocel®, which is an aluminum foam of the open cell variety. The foam is made of 6101 T6 aluminum and has a 10 % relative density (90% of the volume is air) and a linear pore density of 20 pores per inch. The materials investigated for the shell were aluminum and carbon fiber composite. The columns were tested with and without a core and with and without adhesive bonding between the core and shell. The specific energy, which is the energy absorbed divided by the weight, shows a negative effect to having the core, with or without adhesive. The comparison of the ratio of the absorbed energy to the maximum force shows a marginally negative effect as well. This paper presents the methodology of adhesively coupling the aluminum foam cores to the cylindrical shells. A visual presentation of the various failure modes is presented and discussed.