Design of Fiber-Reinforced Cellular Structures with Tensegrity Behavior Manufactured Using 3D Printed Sand Molds

Tensegrity structures provide a high stiffness to mass ratio since all the comprising elements are either in compression or tension. However, they have limited applications since fabrication of such structures is challenging due to their complexity and mainly requires manual assembly of components. The authors look to Additive Manufacturing (AM) as a means to introduce tensegrity behavior in cellular structures to enhance structural performance. Specifically, octet cellular structures are created by casting aluminum into 3D-printed sand molds embedded with continuous wires. In this paper, the authors describe design and analysis of octet cellular structures that feature high strength fibers held in continuous tension. Finite element analysis of 4- point bending test is used to evaluate the effectiveness of embedded fibers. Also, the presence of tensegrity behavior was evaluated using this analysis and testing. The structure with tensegrity behavior was found to be 30 % stronger. The simulation and experimental results were shown to match within 6 % error in the elastic region.