Metamaterial design and continuously adjustable mechanical properties based on novel planetary gear trains

Abstract

Mechanical metamaterials have been pursuing as valuable properties attribute to the unique internal architecture, but are generally limited to the predetermined properties after manufacturing, resulting in the inability to continuously change the properties during application. Aiming for the continuously adjustable property under environments with high reliability requirements, this research developed two types of mechanical metamaterials based on planetary gear train. The principle of continuously adjustable mechanical property and dynamic characteristics of metamaterial based on planetary gear train is researched though a theoretical model of curved beam under varying radial load. Further, mechanical metamaterials based on double-layers planetary gear (DLPG) train and Ravigneaux planetary gear (RPG) train are designed. The compressive elastic modulus, shear modulus, and amplitude-frequency response are calculated and investigated with finite element simulation. The results, with an adjustable range respectively within 9–15 times and 2–3 times in compressive elastic modulus of and shear modulus, show a good agreement between the theoretical and simulated results, and illustrate the adjustability and reliability of the mechanical metamaterials based on planetary gear train. Finally, the potential configurations and applications of metamaterial based on planetary gear train are presented.