Energy Absorption of Sandwich Tubes Under Lateral Loading

The energy absorption of sandwich tubes impacted between two rigid plates was investigated experimentally and numerically in the paper. Based on the collapse patterns observed in quasi-static experiment, several typical sandwich specimens were made and tested. The specimens were placed on the bottom platen of an Instron machine and gained a constant upwards velocity, followed by the impact with the top rigid platen. Their deformation history and load-compression curves were recorded. The energy absorption of sandwich tubes were then calculated and analyzed. Three different crushing patterns have been identified from previous experiments. The dynamic enhancement of energy absorption of the sandwich tubes were only observed in collapse pattern III under the tested velocity up to 10 m/s. Finite element (FE) models using ABAQUS were developed and validated against experimental results and the strain rate effect of metallic foam was considered. They were used to explore the detailed energy-absorption characteristics beyond the experimental range for impact velocities up to 100 m/s. The dynamic enhancement occurred for each configuration of sandwich tubes when the impact velocities were greater than 20 m/s. It was found that increasing the compression velocity leads to an increase in total plastic energy dissipation. Sandwich tubes with a thicker foam core are proved to be the optimum design.