Polyurethane foam core has been considered for sandwich design due to its high stiffness and toughness.
One of the methods of potential improvement of the foam is impregnating it with stiff nanoparticles,
increasing its stiffness and collapse strength. In this paper we use the Mori–Tanaka and the self-consis-
tent methods to estimate an increase in the stiffness of closed-cell and open-cell foams impregnated by
stiff nanoparticles that do not affect foam geometry. Subsequently, the effect of the impregnation of the
foam core on the response of a sandwich beam is demonstrated. The response characteristics considered
in the paper include bending deflections in a three-point test, global buckling and wrinkling loads, and
the effect of the foam impregnation on its compressive collapse stress associated with local instability
of the elements of the foam. Recognizing that the introduction of nanoparticles in the foam material cre-
ates local stress concentrations around the inclusions we also examine the local strength of the impreg-
nated foam using the classical Goodier solution for dilute particles and the Mori–Tanaka based stress
analysis for a finite particle concentration. In addition, we demonstrate the approach to the evaluation
of the resilience of impregnated foam utilizing the dilute approach. While numerical examples concen-
trate on polyurethane foam, the methodologies and conclusions can be extrapolated to any polymeric
foam material reinforced by nanoparticles