Exploring the Real-World Challenges and Efficacy of Internal Coupling in Metastructures: An Experimental Perspective

Metastructures with internally coupled resonators promise enhanced vibration control and energy harvesting capabilities by theoretically enabling multiple bandgaps. This paper investigates the feasibility of these theoretical benefits under practical constraints, particularly the challenge of merging multiple bandgaps in continuous systems. Employing a closed-form analytical approach alongside FEM simulations and experimental validation, the study reveals that while internal coupling can modify bandgap behavior, achieving precise stiffness alignment and bandgap merging remains challenging. The findings indicate that practical applications may not fully realize the predicted advantages and also present more challenges in merging multiple bandgaps created in such metastructures, even for metastructures with advanced manufacturing precision and design optimization. The paper contributes to the understanding of the dynamic behavior of internally coupled metastructures and outlines directions for future research to bridge the gap between theory and application.