Nested Endoskeletal Prestressed Structures

We present the results of a geometrical and numerical investigation on a particular class of tensegrity systems, which we name nested endoskeletal prestressed systems, following a terminology introduced by Kenneth Snelson. These systems are composed by concentric layers of radial bars, “circumferential” cables, and stabilizing cables. After describing how to construct them, we study stability and selfstress in relation to connectivity, number of layers, and geometry. In particular, we find that internal mechanisms need to be eliminated by additional cables in order to ensure stability, and that admissible selfstress states can be determined by establishing selfstress layer-by-layer, starting from the center. This study represents a first step toward the systematic design of this special class of tensegrities, which may find application in robots for rough-terrain locomotion and shock-protection systems.