Enhancement of buckling characteristics for sandwich structure with fiber reinforced composite skins and core made of aluminum honeycomb and polyurethane foam

This experimental study is concerned with enhancing the buckling characteristics of sandwich structure when the 6061-T6 aluminum skins are replaced by carbon fiber reinforced composite for the same aluminum honeycomb and polyurethane core. Such an improvement can be attributed to the high strength to weight ratio of the composite skin while the softer core material acts on a relative base as a better energy absorbent and hence tends to stabilize the failure. This results in much higher post-buckling loads which corresponds to the remaining strength of the structure after the onset of buckling. Sandwich structures with core made of polyurethane foam with different densities were also tested in compression. The buckling load increased with the density of polyurethane up to 280 kg/m 3 while deattachment of the core and skin occurred when the density is decreased below 100 kg/m 3. Compatibility of the skin and core material is shown to play an important role in the buckling behavior of sandwich structure.