Free vibration characteristics and veering analysis of auxetic metamaterial plates

Abstract

Honeycomb-reinforced composite sandwich plates (CSPs) have been widely used in the aerospace field due to their excellent mechanical properties, especially the Auxetic Hexagonal Honeycomb (AHH) sandwich plates with negative Poisson’s ratio effect. However, their vibration characteristics and modal coupling mechanisms have not been studied; therefore, this paper establishes a systematic research method that integrates modelling, fabrication, verification, and analysis. First, this paper develops a semi-analytical dynamic model for the AHH-CSP structure, based on the first-order shear deformation theory (FSDT) and the layer-wise zigzag theory. Second, AHH-CSP specimens are designed and fabricated, and their natural frequencies and modal shapes are determined via impact tests. Then, this paper verifies the accuracy and applicability of the semi-analytical model by combining it with finite element simulations, existing literature, and experimental results, and systematically analyzes honeycomb parameters on structural vibration characteristics. The results show that coupled vibration occurs between different modes of the AHH-CSP structure, thereby inducing frequency veering and mode shape exchange and revealing the inherent patterns of modal coupling. The findings provide both theoretical foundations and experimental support for the engineering application of novel honeycomb sandwich plate structures with negative Poisson’s ratio.