Dynamic behaviour and energy absorption of 1D and 2D regularly packed cells

This paper summarises the studies of dynamic behaviour and energy absorption performance of the following regularly packed cell systems under axial (in ID cases) or in-plane (in 2D cases) impact loading: ID and 2D ring systems, a chain of type II cells, and a 2D honeycomb block. Under impact loading, these packed cells exhibit complicated dynamic behaviour, such as localisation and propagation of the deformation, the dependence of deformation mode on the impact velocity, significant effect of lateral inertia displayed by type II cells, and so on. It is revealed that the early response of these packed cells is dominated by the collision between the striker and the impinged end of the packed cells. Since the dynamic deformation mode of these regularly packed cells is notably affected by the impact velocity, while different deformation modes often lead to different energy absorption capacity and failure mechanisms, particular attention is paid to the determination of mode transition velocities.