Design of a mass-enhanced star-shaped auxetic metamaterial for tailored quasi-static energy absorption and broadband vibration isolation properties

Abstract The development of aerospace structures demands lightweight, multifunctional designs, creating a pressing need for metamaterials that synergistically combine broadband vibration isolation with high energy absorption. This work proposes a mass-enhanced star-shaped auxetic metamaterial (MESSAM), which is inspired by the spring-mass design concept. By combining Bloch’s theorem, finite element analysis, quasi-static compression and vibration isolation experiment (EXP), the energy absorption and bandgap characteristics are systematically elucidated. The results indicate that at a relative density of 39%, the MESSAM attains a densification stress of 8.9 MPa, a specific energy absorption as high as 4.3 J g −1 , and full-band vibration isolation is achieved within the frequency range of 3592–9780 Hz. The comparative analysis of the quasi-static compression EXP and deformation modes shows that the mass units guide and stabilize the auxetic deformation process of the structure, which is critical for achieving high energy absorption. Furthermore, the analysis of the vibrational modes at specific frequencies confirms that the local resonance induced by these additional masses are the fundamental mechanism for broad bandgap formation. Parametric studies further verified that the performance can be custom-tailored through the independent adjustment of key geometric parameters (mass block size, concave depth, independent side wall thickness), thus effectively breaking the performance trade-off among various functions. A core design criterion is derived: incorporating additional mass units into auxetic or periodic structures enables synergistic enhancement of energy absorption and vibration isolation. This work demonstrates the multifunctional integration capability of MESSAM and provides a viable solution to address the performance synergy challenge.