Overview no. 132: The creep of cellular solids

Honeycombs and foams, loaded at low temperatures (T < 0.3T(m)), deform by the elastic deflection, elastic buckling and plastic collapse of their cell walls. At more elevated temperatures, creep contributes to the deformation, which becomes time-dependent. In this paper we develop expressions for the creep-bending of cell walls allowing the creep rate of honeycombs and foams to be predicted from the cell-wall properties and relative density. The analysis follows the general approach [1] of Gibson and Ashby (Cellular Solids, Structure and Properties. Cambridge University Press, Cambridge, 1997), extending it to time-dependent deformation. To assess the validity of the model, a set of creep experiments was carried out on an open-cell aluminum foam. The analysis gives a good description of the experimental results. (C) 1999 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All lights reserved.