Multifunctional hollow lattice metamaterials with broadband vibration isolation and high stiffness and strength

To address the combined challenges of broadband vibration isolation, high load capacity, and lightweight design in complex working conditions such as suppressing combustion chamber pressure oscillations in aerospace launchers and isolating micro-vibrations in spacecraft electronic equipment, this paper proposes a multifunctional lattice metamaterial structure combining wave bandgap regulation with mechanical performance enhancement. The influence of the geometrical parameters of the structure on the bandgap characteristics and mechanical properties was investigated by means of partial decoupling. The results showed that the SBCC (Spherical-node reinforced body-centred cubic) lattice metamaterial possesses a wider bandgap (20.88 kHz). Specific stiffness, specific strength, and specific energy absorption were improved by 164.00 %, 103.05 %, and 103.31 %, respectively, compared with BCC (Body-centred cubic) lattice at equivalent mass. The SOBCC (Spherical-and-octahedral-node reinforced body-centred cubic) lattice metamaterial achieved a lower initial bandgap frequency (20.76 kHz) than SBCC and an elastic wave transmission loss reaching −300 dB at 37 kHz. Furthermore, wider bandgap hybrid structures were designed based on the bandgap superposition effect. This work provides new ideas for the design of multifunctional lightweight metamaterials with both vibration isolation performance and high load capacity in complex engineering applications. • Lightweight hollow metamaterials with broadband vibration isolation and high load capacity were designed. • Multifunctional metamaterials with wider band gap (20.88 kHz) for vibration isolation. • The mechanical properties of the designed multifunctional metamaterials have been enhanced. • Hybrid structures based on the bandgap superposition effect were designed.