DYNAMIC PROPERTIES OF SANDWICH PANELS WITH METAMATERIAL CORE

This study investigates the vibrational properties of honeycomb panels composed of metamaterials through a detailed experimental analysis. The research focuses on plate structures with honeycomb cores that are fabricated using advanced 3D printing techniques. These cores are designed to exhibit chiral characteristics and a negative Poisson ratio, which are key attributes that influence their mechanical performance. By leveraging metamaterial properties, these structures can achieve unique dynamic behaviors that differ significantly from conventional honeycomb panels.The primary objective of this study is to evaluate the dynamic response of these structures, particularly in terms of their natural frequencies, mode shapes, and damping characteristics. Additionally, the study aims to explore how these vibrational properties change under varying temperature conditions, which is critical for practical applications in aerospace, automotive, and other engineering fields. Understanding the impact of temperature on mechanical properties is essential for designing resilient materials that can perform reliably under fluctuating environmental conditions.To achieve these goals, the core layers of the honeycomb panels are fabricated from polylactic acid (PLA), a widely used thermoplastic known for its ease of 3D printing and mechanical stability. Different core configurations with varying geometric patterns are employed to analyze their influence on the dynamic behavior of the overall structure. These variations allow for a comparative analysis of how different honeycomb patterns affect vibrational properties, particularly in terms of stiffness, damping, and energy dissipation. The experimental approach consists of two primary testing methods. First, impact hammer testing is used to determine the natural frequencies and mode shapes of the honeycomb panels. Second, a base excitation is performed using a shaking table within a controlled climate chamber. This setup simulates real-world operating conditions by subjecting the panels to dynamic loading while monitoring their responses under different temperatures. Temperature variations are expected to significantly affect both the elastic and dissipative properties of the materials, as well as the overall structural behavior of the metamaterial-based honeycomb panels. By systematically analyzing these effects, this study contributes to a deeper understanding of the vibrational performance of 3D-printed metamaterial structures. The findings will help guide the design of advanced engineering materials with tailored dynamic properties for specialized applications.