In-plane crushing and energy absorption performance of multi-layer regularly arranged circular honeycombs

The dynamic deformation modes, plateau stresses and energy absorption performance of multi-layer regularly arranged circular honeycombs are investigated numerically under the in-plane crushing loadings at the impact velocities 3-250. m/s, with aim to disclose the influences of configuration parameters and impact velocity on them. The numerical results are presented in the forms of diagrams, curves and tables. With increasing impact velocities, the double "V" -shaped (quasi-static homogeneous mode), "V" -shaped (transition mode) and "I" -shaped (dynamic mode) collapse bands are observed in turn. A simplified energy absorption model is put forward and employed to describe the energy absorption performance. It is shown that the optimal energy absorption per unit volume is related to dynamic plateau stress and dynamic densification strain and that the optimal energy absorption efficiency is the reciprocal of dynamic densification strain. From physical analysis and discussion, the empirical formulas of critical velocity of mode transition, plateau stress and dynamic densification strain are given based on the numerical results.