In the past decades, auxetic structures have received great attention because of their unique properties and outstanding performance over the traditional materials. However, the inherent porosity significantly reduce the moduli of the structures, making auxetic structures inappropriate for load-bearing components. This paper introduces a rounded re-entrant honeycomb (RH) pattern, in which the rounded corners stiffen the traditional RH pattern by suppressing the hinging mechanism. Four design parameters were identified to define a rounded RH unit cell, and the effect of each of them on structure properties was numerically studied. The results demonstrated the extended tunable range of mechanical properties and the possibility of building lightweight and stiffer structures, as well as significantly improved tensile and shear moduli. It is also noticed that the Poisson's ratio shifts towards positive as the radius of the rounded corner increases. Several design strategies were proposed for achieving different design goals. The proposed rounded RH pattern could be an alternative for the existing RH pattern design, especially in the applications requesting for the lightweight and rigid auxetic structure.
- lightweight tunable structures
- rounded re-entrant honeycomb