Investigation of novel 3D-printed diatomic and local resonant metamaterials with impact mitigation capacity

A novel dual local resonance metamaterial chain, at a low frequency regime ( < 200 Hz), is designed and fabri-cated using selective laser sintering technology for characterization of wave attenuation and impact mitigation, consisting of a main structure and cantilever-in-mass resonators as a periodic sub-structure. The dispersion char-acteristics and mode polarization of metamaterial chains with various resonators are studied using a mass-spring model and finite element modelling simulation. The results clearly demonstrate the bandgap of the dual reso-nance system is extended by both the local resonance and diatomic resonance mechanisms. A parametric study is established to optimize the bandgap ratio, revealing that the bandgap of the design can be shifted by changing the stiffness ratio between two resonators in the sub-structure. The wave attenuation in the frequency domain ob-tained from impact modal tests exhibits a good agreement with computational results. In particular, the dynamic load attenuation capacities of the metamaterial chains under different impact durations are studied using impact mitigation tests, which show that the dual resonance design has the best attenuation performance under impact force, where the transmission rate is driven down to 0.2, compared with 0.48 for the design without resonators.

Automated summary

A novel dual local resonance metamaterial chain is designed and fabricated for wave attenuation and impact mitigation purposes, with an extended bandgap through both local resonance and diatomic resonance mechanisms. The optimized design shows excellent performance in wave attenuation and impact mitigation, with the best transmission rate driven down to 0.2 compared to a design without resonators at 0.48.