Reducing machine vibration and noise contributes to comfort in mobility and a variety of other living environments, as well as to product safety. We are advancing research into new vibration-damping structures and materials that efficiently use material resources to revolutionize silence, and into their design theories. For example, by deriving equations for the propagation characteristics of elastic waves inside shell architectures with periodic structures, we enabled the design of bandgap periodic structures that do not propagate vibration in specific frequency bands. We applied this method to design a metamaterial structure using a pulp mold~{*1}, and combined the metamaterial bandgap effect with material damping to achieve a vibration-damping component that significantly reduces vehicle vibration and noise over a wider frequency range than before.
*1: Jointly developed with TOYOTA AUTO BODY CO., LTD.
Bandgap design method for periodic structures (top) and application example to a pulp mold (bottom)