Energy absorption of thin walled tube filled with gradient auxetic structures-theory and simulation

In recent years, auxetic structures have been applied in the energy absorption field due to the unique mechanical properties. Inspired by foam filled structures, this study proposes a thin walled structure filled with double arrowed auxetic structure and investigates the energy absorption characteristics. The gradient configuration is introduced to improve the energy absorption performance. The effects of the gradients on the energy absorption are investigated. A theoretical model is also established to predict the energy absorption to quantify the energy dissipated due to thin walled tubes, gradient auxetic structures and their interactions. The accuracy of the theoretical model to predict the energy absorption characteristics is validated through the numerical simulations.