Elastic and vibrational properties of a regular tensegrity structure

Invented by R. Buckminster Fuller and Kenneth Snelson between 1948 and 1961, tensegrity structures consist of stiff rods connected to flexible strings such that no rod is joined to any other rod. A prestressed tensegrity structure, in which all the strings are under tension, maintains a distinct shape, deforming slightly under a load. For the present study, tensegrity masts consisting of repeated layers of three‐, four‐, or five‐rod patterns were constructed. With 15‐cm rods, an eight‐layer mast is 50 cm long and has a diameter of 20 cm. All masts exhibited a hysteretic nonlinear elastic response to applied stress along the major axis. Young’s modulus for the eight‐layer mast ranged from 2500 to 5000 Pa at 8% strain. Increasing the tension in the strings by a factor of 2 resulted in a 14% increase in the Young’s modulus at small strains. Implications of this nonlinear behavior for wave propagation along the axis of a tensegrity mast is currently being investigated. Results will be shown for resonance frequencies as a function of drive amplitude. [Work supported by the Murdock Charitable Trust and Central Washington University.]