Strain Rate Behavior of Closed-Cell Al-Si-Ti Foams: Experiment and Numerical Modeling

Abstract

We present a combined experimental and numerical study on the strain rate effect of closed-cell Al-Si-Ti foams having different relative densities fabricated using the powder metallurgy foaming technique. The high strain rate tests were conducted with split Hopkinson pressure bar technique at 800 to 2500 s⁻¹. Two-dimensional mesoscale finite element models were created from tomographic images of the homologous foam. The rate sensitivity of the foam originates mainly from that of its parent material, increasing with increasing relative density. Stress elevation due to other effects, such as micro-inertia, shock wave, and gas pressure in individual cells, is negligible.

Keywords:

• metallic foams
• powder metallurgy
• split Hopkinson pressure bar
• pulse shaper
• mesoscale finite element model
• dynamic compression