Multi-stability Property of Magneto-Kresling Truss Structures

The Kresling truss structure, derived from Kresling-ori, has been widely studied for its bi-stability and various other properties that are useful for diverse engineering applications. The stable states of Kresling trusses are governed by their geometry and elastic response, which involves a limited design space that has been well-explored in previous studies. In this work, we present a novel magneto-Kresling truss design that involves embedding nodal magnets in the structure, which results in a more complex energy landscape, and consequently, greater tunability under mechanical deformation. We explore this energy landscape first along the zero-torque folding path and then release the restraint on the path to explore the complete two-degree-of-freedom behavior for various structural geometries and magnet strengths. We show that the magnetic interaction could alter the potential energy landscape by either changing the stable configuration, adjusting the energy well depth, or both. Energy wells with different minima endow this magneto-elastic structure with an outstanding energy storage capacity. More interestingly, proper design of the magneto-Kresling truss system yields a tri-stable structure, which is not possible in the absence of magnets. We also demonstrate various loading paths that can induce desired conformational changes of the structure. The proposed magneto-Kresling truss design sets the stage for fabricating tunable, scalable magneto-elastic multi-stable systems that can be easily utilized for applications in energy harvesting, storage, vibration control, as well as active structures with shape-shifting capability.

TRUSS DESIGN CALCULATION

the completeness of the truss design calculation is its configuration and dimensions when specifying the type of loading, material characteristics and directive dimensions. The problem of equilibrium stability with an unknown location of compressed rods hindered the optimization of the topology and geometry of the truss. The proposed variational method of truss synthesis is based on the principle of possible operation and generalization of the variational principles of Lagrange and Castigliano by expanding the functional space of geometric parameters. The solution of a physically linear isoperimetric problem for a given volume of the truss material allowed to establish its quasi-equal stress, which became the design criterion for the formulation of the geometry optimization problem. Its condition is the stationarity of the functional with respect to variable geometric parameters for a given flexibility of compressed rods. The iterative procedure, caused by a change in the initially accepted signs of longitudinal forces, is based both on their direct adjustment and on the change in the flexibility of individual rods. The global minimum of potential strain energy of the optimal truss is accompanied by a global minimum of material consumption. The proposed software allows to conduct automated design calculation of the truss. An example of designing a mechanical truss is considered.

A Three-bar Truss Design using Single-solution Simulated Kalman Filter Optimizer

Three-bar truss is a structure that is important in the field of civil engineering. Design of the three-bar truss is thus an interesting problem in engineering. Metaheuristic approach has been employed to get near-optimal solution of this problem. A study to investigate the effectiveness of a new single-solution simulated Kalman filter (ssSKF) algorithm in three-bar truss design is presented in this paper. The solution obtained by the ssSKF is as good as hybrid lightning search algorithm-simplex method and better than solutions produced other algorithms in literature.