Zero-thermal-expansion metamaterial with broadband vibration suppression

Although conventional metamaterials possess extraordinary properties, they cannot meet the practical requirements of engineering structures subjected to both temperature fluctuations and vibration excitations. To bridge this research gap, this paper proposes a novel dual-functional metamaterial with zero thermal expansion and broadband vibration suppression. Inspired by the thermal mismatch and band gap effects, we present an innovative design strategy that incorporates star-shaped re-entrant lattices and locally rudder-shaped struts with two-phase materials. To effectively guide the coupled design, a theoretical model accounting for stretching-bending deformations is established to predict the thermoelastic behavior of the metamaterial. Moreover, a parameterized dynamic model using the spectral element method is developed to study the vibration characteristics. Particularly, the spectral formulation of curved Timoshenko beams is derived, including in-plane and out-of-plane vibrations. The comparisons between theoretical predictions and finite element simulations validate the accuracy of analytical models in characterizing thermal deformations and vibration responses. Finally, the case studies shed light on the underlying formation mechanisms of zero thermal expansion and multiple band gaps, while also unveiling the effects of geometric parameters on the performance of such dual-functional metamaterials. Our innovative design strategy and analytical methodology not only offer appealing alternatives for engineering applications but also push the boundaries of metamaterial properties by enabling the transition from single- to dual-functionality.