Energy absorption of graded foam subjected to blast: A theoretical approach

Highlights: • High velocity crushing of continuous graded foam is theoretically examined. • Study suggests that the graded foam outperforms its homogeneous counterpart. • The denser part should be placed at the loading end. - Abstract: Energy absorption of graded foam subjected to blast is investigated, in which the high velocity crushing of foam is modeled with shock theory and rigid-perfectly-plastic-locking idealization. The characteristics of a typical blast are taken into account when determining the foam density profile. Different from the homogeneous foam, the graded foam density variation is designed largest at the loading end and smallest at the supporting end, with an exponential decay in between. It is found that, subjected to the same blast load, the total input energy, in fact the energy to be dissipated by the cladding, decreases with increasing density gradient. The final foam deformation with larger density gradient is smaller.