Abstract:

A design idea for single-component metamaterial plates is proposed to achieve the thermal stability of flexural wave bandgap by the perforated and pre-curved patterns. The band structure analysis suggests that perforation can release part of the in-plane thermal expansion to weaken the softening effect of thermal stress. Introducing pre-curved components to the perforated structure will stop the decrement of the bandgap frequency in thermal environment, and even make the frequency higher with appropriate structural parameters. The bending stiffness of the heated plate is enhanced by the thermal deflection induced stiffening effect of the pre-curved components. The segmented pre-curved component presents a strong ability to resist the thermal influence on the flexural wave bandgap. A simplified model is established for the local structure of the pre-curved component. The theoretical calculations explain the thermally induced frequency increment of the bandgap and the discrepancy in the thermal response between the two pre-curved models. The transmittance of flexural wave validates the effectiveness of the proposed design.

Key words: metamaterial plate, flexural vibration, bandgap, perforation, pre-curved pattern, thermal stability