Abstract
Tensegrity structures are a special class of lightweight truss structures, where all truss elements
are axially loaded and tensile truss elements are made of strings. This paper presents
the dynamic analysis of a tensegrity structure by comparing a finite element model with an
identified model obtained from experimental data. Experimental data is obtained by placing
a three stage tensegrity structure on a shaker table and measuring frequency responses between
the moving support and multiple accelerometers placed on the structure. An identified
Single-Input-Multiple-Output (SIMO) linear model is found by a SIMO curve fitting of the
measured frequency responses. To complete the dynamic analysis, the estimated model along
with the identified resonance modes and damping coefficients are used to compare and fine
tune a fine element based model.
Keywords: tensegrity structure, dynamic analysis, frequency domain identification, finite element
models
1 Introduction
Truss structures, where all truss members are axially loaded and separated in tensile and compressive
load carrying members, form a basis for the design of tensegrity structures. As such,
tensegrity structures differ from regular trusses by purposefully designing all tensile elements to
be strings. The result is a lightweight structure with comparable stiffness properties to regular
truss structures. Tensegrity structures were first introduced as an art form in 1948 by Snelson
(1965). The work by Fuller (1962) recognized their engineering values.
Tensegrity structures can be designed such that no compressive elements are in direct contact
(class 1 tensegrity). Connections between compressive elements are achieved by flexible tensile
string elements. For the design of these flexible tensegrity structures much attention has been
paid to the static construction and mechanical stability of the structure (Pellegrino and Calladine
1985), (Pellegrino 1989) and (Motro 1992). For a comprehensive static analysis of tensegrity
structures one is also referred to Sultan (1999) or Sultan et al. (2003). Due to the inherent tunable