Compression behavior and energy absorption capacity of stiffened syntactic foam core sandwich composites

Phenolic syntactic foam sandwich composites are potential materials for aerospace and marine applications because of their good strength to weight ratio, stiffness to weight ratio, fire resistance and better energy absorption characteristics. In the present work, syntactic foam is prepared by uniform mixing of cenosphere and phenolic resin in equal proportions. The effect of stiffening the syntactic foam core by resin impregnated paper honeycomb (RIPH) structure on compression behavior and energy absorption capacity of sandwich composites is experimentally investigated under flatwise and edgewise loading configuration. Bare RIPH core and only syntactic foam core sandwich composites are also investigated for comparison purpose. The results show that RIPH incorporated syntactic foam has the highest compressive properties and energy absorption capacity compared to only syntactic foam core sandwich composites. Microscopic features of syntactic foam fragments tested under flatwise compression are also investigated to predict the failure mode.