Novel Form-Finding of Tensegrity Structures Using Ant Colony Systems

Abstract

Tensegrity structures have remarkable configurations and are drawing the attention of architects and engineers. They possess inextensional mechanisms and self-stress states at a static equilibrium configuration under no external loads. For geometry with its nodes fixed, different connectivity patterns of the compression bars and tension cables might bring some novel tensegrity structures. Thus, form-finding is the key to designing novel tensegrity structures. Here, we develop a discrete optimization model for the form-finding and convert it into a modified traveling salesman problem (TSP). The ant colony system (ACS) is used to search for feasible solutions, where all the predetermined nodes are taken as different cities in the network. An objective function that considers the stability and the relative stiffness is developed to obtain the optimized configurations of tensegrity structures. Examples based on some regular geometries (including a hexagon and two polyhedra) and two nonregular geometries are carried out using the proposed technique. Many different configurations of the pin-jointed assemblies are transformed into interesting tensegrity structures. To verify the proposed method, some physical models are constructed and compared to the tensegrity structures obtained from the form-finding process. We conclude that this novel algorithm can be applicable to the form-finding of both regular and nonregular tensegrity structures.

Enumeration–screening method for the design of simple polygonal tensegrities

“…We have obtained more types of topologies can be obtained in comparison with some previous schemes (e.g. [33][34][35]).…”

“…In addition, some biomechanical models have been proposed on the basis of 2D tensegrities to investigate the dynamic behaviour of proteins, cells, tissues and organs [30][31][32]. To date, however, only three main types of 2D tensegrities have been reported: quadrilateral, hexagonal and octagonal [33][34][35]. This limitation of structural types hinders their further applications, since some required functions may not be achieved by the existing classical 2D structures.…”

Inverse form-finding for tensegrity structures

“…The method proposed by [16] finds a topology for a given set of nodes using ant colony systems. The researchers try to find a stable tensegrity by maximizing the minimum eigenvalue of the tangent stiffness matrix.…”

Elastostatic Modeling of Multi-Link Flexible Manipulator Based on Two-Dimensional Dual-Triangle Tensegrity Mechanism

“…In order to find tensegrity structures that better suit the desired application different optimization methods were applied. For example, Chen et al used ant colony optimization for tensegrity structure optimization [17]. Ehara and Kanno used mixed integer programming to minimize the number of cables and remove redundant self-equilibrium modes [18].…”