A novel honeycomb sandwich cylindrical shell with dual deformation mode for circumferential vibration isolation and enhanced stiffness

The vibration isolation applications of the traditional periodic honeycomb structures (PHSs) are limited by the poor stiffness of the support frame, while the embedded resonators inevitably compromise the lightweight property. In this paper, a novel dual deformation mode honeycomb (DDMH) is proposed through the design of deformation compatibility and internal contact behavior. The static support performance of the DDMH is investigated through the quasi-static compression considering internal contact. A theoretical dynamic model of the curvature DDMH is proposed based on the cylindrical periodic boundary description by Bloch's theorem to explore the effect mechanisms of the typical design parameters on circumferential band gap (CBG) characteristics. In addition, the effects of the excitation form and curvature on the circumferential vibration transmissions of the DDMH are intensively discussed though the modal displacement analysis. To verify the vibration isolation performance of the sandwich, the global transmission responses of the cylindrical shell with the DDMH sandwich are studied by the experimental measurements and numerical simulations. The results indicate that the static stiffness of the DDMH is significantly enhanced when the transformation of the deformation mode triggered by the designed internal contact is produced. The main circumferential vibration isolation band of the DDMH cylindrical shell is strongly correlated with the CBG of the sandwich unit. Therefore, this study provides an innovative solution for the integration of static and dynamic mechanical properties of the PHSs through the design of deformation contact behavior, which can be applied to the engineering implementation of the lightweight sandwich cylindrical shell with excellent static support and vibration isolation performance.