Energy absorption of foam-filled circular tubes with braided composite walls

Braided glass-fibre/epoxy circular tubes with polymer foam cores are loaded in tension and in compression, and the energy of deformation is measured. Theoretical models of tube deformation are developed, and are used to predi ct the energy absorption as a function of tube wail strength, the ratio of tube wall thickness to tube diameter, and the density of the foam. The ener gy per unit mass and energy per unit volume are optimised with respect to t he relative density and geometry. It is found that foam-filled braided circ ular tubes exhibit promising energy absorbing characteristics, due to a com bination of energy absorption by the polymeric foam core and by the glass/e poxy braided tube. (C) 2000 Editions scientifiques et medicales Elsevier SA S.