Analysis of mechanical response of aluminium honeycomb subjected to indentation

Aluminium honeycombs is a lightweight cellular material and a good energy absorber. In different engineering applications, it is usually used as structural components. Comprehensive study has been conducted to analyse the compressive behaviour of aluminium honeycombs. However, research related to mechanical response of aluminium honeycombs material subjected to different type of loadings, such as indentation, is still limited. In this paper, experimental and numerical studies were conducted to investigate the deformation mechanism and energy dissipation of a HEXCELL® aluminium honeycomb subjected to dynamic indentation. A high speed INSTRON machine was used to conduct dynamic tests at velocities of 0.5 m/s and 5 m/s. Numerical analysis was conducted using ANSYS LS-DYNA at velocities of 5 m/s, 15 m/s and 25 m/s. The simulation results were in good agreement with the experimental results in terms of stress-strain curve profile and deformation mode. In the experiment, it was found that with the increase of velocity (strain rate) the average plateau stress of indentation also increases which was validated in the numerical analysis. The deformation of aluminium honeycombs under indentation showed that the compression of hexagonal honeycomb cells under the indenter and also tearing of honeycomb cell walls along the four edges of the indenter. The dissipation of energy in compression and tearing was calculated and discussed. The effect of loading velocity on the plateau stress and energy absorption was also analyzed