A New Approach to Nonlinear Dynamic Modeling and Vibration Analysis of Tensegrity Structures

Abstract

Abstract Tensegrity structures have experienced continued research and development interests in the past several decades. Revealing dynamic characteristics of a tensegrity structure, for example: vibration analysis, is an important objective in structural design and analysis. Traditional dynamic modeling methods are inaccurate in predicting dynamic responding of a tensegrity structure, due to their neglection of internal displacements of structure members. To solve this issue, a new nonlinear dynamic modeling method for tensegrity structures is proposed in this paper. This method defines position of a structure member as a summation of boundary-induced terms and internal terms in a global coordinate system. A nonlinear dynamic model of a tensegrity structure is derived from Lagrange equation, as a system of ordinary differential equations. This dynamic model can be linearized at an equilibrium configuration for vibration analysis. As shown in simulation results, the proposed method can predict natural frequencies of a tensegrity structure with a better accuracy than the traditional methods. Unlike the traditional methods that can only predict dynamic responses in a low frequency domain, the proposed method can also reveal dynamic responses of a tensegrity structure in a higher frequency domain by only using a small number of internal terms.