Abstract：The curved-wall honeycombs have negative stiffness characteristics, which can absorb energy and isolate shocks during large deformations. They can recover themselves instead of being crushed like the traditional honeycombs after the impact loads. In this paper, the curved-wall negative stiffness honeycombs are used as the core layer and then the dynamic model of the sandwich plate is established. The equivalent elastic parameters of the curved-wall honeycomb cells are deduced including the Young's modulus, Poisson's ratio and the shear modulus. Afterwards the negative stiffness honeycomb cells are arranged periodically as the core layer of the sandwich plate. By using the Reddy’s higher-order shear deformation theory, Von-Karman large deformation relationship and Hamilton principle, the nonlinear dynamical equations of the honeycomb sandwich plate are derived. The Navier method is used to calculate the natural frequencies of the plate under the boundary conditions of simply supported on four sides. Simultaneously, the finite element model of the sandwich plate is established by the solid units, and the natural frequencies are derived by using ABAQUS software. The results show that the natural frequencies from the two methods are in good consistency, which verify the validity of the equivalent elastic parameters of the curved wall honeycomb layer. Finally, the variation characteristics of natural frequencies of the sandwich plate with different core thickness, different core thickness ratio and different curved-wall thickness are discussed when the energy absorption capacity of the honeycomb cells is better. The results obtained in this paper will provide a basis for further research on the dynamics of negative stiffness honeycomb plates and will give certain guidance for the applications of negative stiffness honeycombs to sandwich structures and vibration isolation mechanisms.
2022, Vol. 43 
