Nanoclay syntactic foam composites—High strain rate properties

The effect of nanoclay on the high strain rate mechanical properties of syntactic foam composites is studied. Nanoclay syntactic foam composites are fabricated with 10, 30 and 60% microballoon volume fractions, each having 0, 1, 2 and 5% volume fraction of nanoclay. High strain rate tests using split Hopkinson pressure bar (SHPB) apparatus are performed on all types of composites. Quasi-static tests are also carried out on MTS-810 machine to compare the results with the dynamic SHPB results. It is found that inclusion of 1% nanoclay volume fraction gives the optimum enhancement in peak stress and modulus of nanoclay syntactic foam composites. In addition, specimens tested at high strain rate are shown to exhibit higher stress and modulus compared to those tested at low strain rate. Scanning electron microscopy is performed to study the fracture behavior under different loading rates.