Bifunctional 3D lattice metamaterials for vibration attenuation and crushing resistance

The engineering application demand for multifunctional mechanical metamaterials has increased remarkably, and structural morphology design for achieving the collaborative optimization of multi-physical functions has emerged as a critical research direction. Based on single-phase materials, this paper proposes a bifunctional 3D lattice structure integrating low-frequency vibration suppression and energy absorption properties.​ By introducing the local resonance mechanism to construct low-frequency bandgaps, vibration attenuation in the range of 0–320 Hz is realized, with the minimum onset frequency of the complete bandgap reaching 82.57 Hz. This breaks the limitation that traditional local resonance metamaterials depend on mass-substrate impedance mismatch.​ Local support rods (SR) and connecting rods (CR) regulate the deformation modes and energy dissipation paths under compressive impact, forming a multi-stage progressive energy absorption mode. Furthermore, the auxiliary structure has no additional mass load and exhibits a high degree of freedom in bandgap tuning.​ The study also verifies the potential of bandgap tuning under external forces and establishes a functionally graded design strategy, providing an active means for the dynamic regulation of vibration control. This work offers a new paradigm for the cross-scale design of multifunctional mechanical structures and metamaterials under complex working conditions.