In-plane crushing of a novel sinusoid-curved honeycomb under static and dynamic loadings

The in-plane crushing response of a novel honeycomb consisting of sinusoid-curved ligaments is comparatively analyzed under quasi-static and dynamic loadings using numerical and theoretical methods. The finite element models for ABAQUS/Explicit are validated against the experimental results obtained from the quasi-static tests on the additively manufactured translational-sinusoid honeycomb (TSH) and symmetrical-sinusoid honeycomb (SSH). Quantitatively, the effect of impact velocity and relative density on the deformation mode is revealed by summarizing the deformation maps of SSH and TSH. It implies that the critical velocities at which the transformation of deformation mode happens are larger for SSH than those for TSH. Cells of TSH prefer to be tightly stacked together due to the chirality-liked configuration, whereas the symmetrical configuration strengthens the buckling resistance of SSH cells and the provisional and full densification states would sequentially experience in the crushing process. Investigation on the crushing performance further revealed that the crushing strength and the energy absorption capacity of SSH are slightly higher than those of TSH. In contrast, the densification strain of TSH is larger than that of SSH for a wide range of impact velocity. Regarding the deformation mechanism of representative units, theoretical models are proposed to evaluate the crushing strength of the sinusoid-curved honeycombs. Good agreement between theoretical predictions and numerical results is obtained under both quasi-static and dynamic loadings. Moreover, the effect of the cell topology on the mechanical performance of sinusoidal-curved honeycomb is discussed.