Effect of strain rate and relative density on compressive deformation behavior of aluminum cenosphere syntactic foam

The compressive deformation behavior of aluminum cenosphere syntactic foams of varying densities and cenosphere sizes have been studied at different strain rates (from 0.01/s to 10/s). The plateau stress, densification strain, energy absorption and strain rate sensitivity parameter as a function of relative density, strain rate and cenosphere size have been examined. Densification strain is found to be almost invariant to relative density, strain rate and cenosphere size. But, the plateau stress and energy absorption of syntactic foams are influenced by the relative density and cenosphere size. However, plateau stress is found to be almost invariant to the strain rate. The energy absorption is marginally higher in case of syntactic foam with coarser cenosphere at higher strain rate, whereas reverse is true at lower strain rate. This is attributed to the differences in deformation mechanism at different strain rates.