INVESTIGATION ON THE DYNAMIC COMPRESSIVE BEHAVIOR AND ENERGY ABSORPTION PROPERTIES OF ALUMINIUM-SILICON FOAM

The dynamic mechanical properties of aluminum-silicon foams were investigated by using a spit Hopkinson pressure bar (SHPB), the dynamic stress-strain curves were obtained at strain rates ranging from 1400s-1 to 2500s-1, and compared with the quasi-static compressive results, the effect of the strain rate on the compressive strength and absorption efficiency was analyzed. During the experiment, according to the low impedance of aluminum-silicon foams, a LC4 aluminum alloy pressure bar and a semiconductor strain gauge were employed to ensure the reliability of the experimental results. The results showed that: the strain rate has an obvious effect on the flow stress of the aluminum-silicon foam, the flow stress increases with the increase of the strain rate; there is an oscillation in flow stress during elastic limitation due to inertia efficiency and collapse of the cells, and the oscillation stress increases with increasing strain rate. The energy absorption efficiency of the aluminum silicon foam at various strain rates was also discussed.