Design and impact response of 3D-printable tensegrity-inspired structures

Abstract

Recent studies demonstrate the potential of tensegrity structures as unique building blocks for architected lattices (metamaterials). Key tensegrity characteristics, such as elastic response under severe deformation, high strength-to-weight ratio, and nonlinear behavior, make these structures appealing for dynamic applications. A new method of tessellating tensegrity unit cells with elastically buckling struts in three dimensions has opened new avenues for metamaterials with superior mechanical properties. However, traditional fabrication methods for tensegrity structures are cumbersome and do not allow accurate control of the level of member prestress. To overcome these limitations, we present a design of a 3D-printable, single material structure which has comparable strain energy capacity and compressive response as a tensegrity structure with buckling struts. The structure's geometry maintains key tensegrity characteristics, thus generating an equivalent mechanical response. Numerical simulations inform quasi-static compression experiments and dynamic drop weight impact tests. The structure's responses correspond well to the pin-jointed tensegrity, exhibiting desirable characteristics such as post-buckling stability, resilience under severe deformation, high elastic strain energy absorption, and load-limitation. This work is the first to experimentally corroborate theoretical studies of buckling tensegrity structures. We conjecture that the structure presented here has unique potential as a unit cell for manufacturable tensegrity-inspired metamaterials. Keywords: Tensegrity, Metamaterials, Dynamic impact, 3D-printing, Buckling, Architected unit cells