Analysis of Impact Resistance of Aluminum Hyperboloid Array Metastructure

Metastructures are widely applied in the design of various impact protection structures. To enhance the protective performance of the structures under low-velocity impacts, an aluminum hyperboloid array metastructure (AHAM) was proposed and fabricated by three-dimensional (3D) printing technology. The material point method was employed to simulate the dynamic response of the AHAM under different impact heights, and a series of drop hammer impact experiments were performed in this study. The impact deformation and energy-absorbing mechanisms of the AHAM target plate were investigated in depth using numerical simulation of the material point method and drop hammer experiments. The dynamic response of the AHAM, including acceleration, plastic deformation, impact energy, strain, and stress distribution, was quantitatively analyzed. The acceleration response spectra of the AHAM were calculated to identify the sensitive frequency range that caused the greatest impact damage. The results show that the AHAM can effectively absorb and dissipate impact energy without the addition of energy-absorbing materials. The AHAM presented outstanding impact resistance performance. Compared with a single-layer aluminum plate (SLAP) made of the same material and with an equivalent area, the peak acceleration of the AHAM can be reduced by up to 67.33%. The maximum equivalent strains of the AHAM backplate were only 11.21%–16.99% of the equivalent strain in the collision contact area of the faceplate under different impact heights.