Authors: Harrison Denning, Ammon Bullinger
Mentors: Jeff Hill
Insitution: Brigham Young University
Tensegrity Structures, in their most basic form, consist of rigid bar members held together by cables or strings, with bars being under pure compressive stress and strings being solely under tension. These structures are valued for their high strength-to-weight ratios and unique damping and stiffness properties. Each of these characteristics are wholly dependent on cable tension between the bar members, and structure behavior varies based on how much or how little tension is in each cable. Current research has not established an easy or repeatable way to accurately measure or precisely set the tension in these cables. Our research suggests a novel application of acoustic string frequency measurement to accurately measure the tension in tensegrity cables and pairs this work with a simple construction technique broadly applicable to tensegrity structures. The use of precise cable winding is applied to tensegrity to allow easy construction and small changes to cable tension. A method of measuring string vibrations with a microphone and off-the-shelf software is applied to then measure the tension accurately within each cable member. These methods provide an easily generalizable method for constructing tensegrity models and a high degree of accuracy in measuring the tension in tensegrity cables. These developments may in the future be paired with computational algorithms to create easy instructions on how to adjust individual cable tensions to achieve structure-wide characteristics. This ability will allow for the accurate construction of physical tensegrity models that can better replicate desired characteristics of stiffness and strength currently represented primarily in computer simulations.