Compressive Behavior of Isogrid Columns Fabricated with Bend-Forming Harsh Bhundiya * , Fabien Royer † , and Zachary Cordero ‡ Massachusetts Institute of Technology, Cambridge, MA, 02139 In this study, isogrid columns used in various space applications are made using a novel in-space manufacturing process termed Bend-Forming. The process uses a machine that bends a continuous strand of wire at specific locations, to form a flat lattice. Several straight wire members are attached at the bend locations using 3D-printed joints, and the lattice is then rolled to form a 3D column. Four columns with varying geometric parameters are fabricated. Compression tests are conducted on these columns, and their buckling and post-buckling behavior is investigated. These experiments show that the structures undergo a smooth formation of buckling deformations, and that contrary to thin-shell columns, they do not exhibit an abrupt destabilization past their first bifurcation. A finite element model is then implemented and numerical results are compared to the experimental responses. The comparison highlights the importance of the joint compliance in the initial response of the structure and identifies the need for modeling softer joints. Nonetheless, the model accurately predicts the maximum loads the columns can withstand and highlights the imperfection-insensitive nature of these structures, as compared to conventional shell structures. I. Nomenclature  = Young’s Modulus, GPa  = column height, m  = column diameter, m  = triangle side length, m  = Poisson ratio II. Introduction There is presently resurgent interest in constructing large space structures via in-space manufacturing techniques (ISM) which form raw feedstock materials into structures on orbit. ISM ofers the unique opportunity for on-demand fabrication of structures optimized for the space environment, potentially enabling larger designs than with conventional deployable structures. A variety of ISM methods have been proposed for space, such as additive manufacturing of structures from metallic or fber-reinforced composites[1]; thermoplastic extrusion of CFRP trusses [2, «]; and deformation processing of trusses through plastic deformation [»]. A recent analysis comparing these proposed ISM methods [5] shows that deformation processing of metallic feedstock has the lowest specifc energy consumption and can thus achieve fast build rates on orbit, making it an attractive manufacturing method for space. Motivated by this analysis, here we focus on a specifc deformation process for space, termed Bend-Forming, which uses CNC wire-bending and self-locking joints to form a continuous wire into lightweight truss structures. To fabricate larger trusses from wire feedstock via Bend-Forming, a bend path comprising a sequence of straight sections and bends is prescribed to the wire bending machine, such that the straight sections serve as truss members and the bends serve as truss nodes. Joints are then placed at the nodes to hold the wire, resulting in a stif truss structure. Fig. 1 shows exemplar reticulated shell structures fabricated with Bend-Forming. An understanding of the structural response of Bend-Formed shells is essential to designing and manufacturing optimal truss structures. The reticulated trusses fabricated with Bend-Forming are made of continuous wire with * Graduate Student, Department of Aeronautics and Astronautics, 77 Massachusetts Avenue, Cambridge, MA 021«9, AIAA Student Member † Postdoctoral Researcher, Department of Aeronautics and Astronautics, 77 Massachusetts Avenue, Cambridge, MA 021«9, AIAA Member ‡ Boeing Assistant Professor, Department of Aeronautics and Astronautics, 77 Massachusetts Avenue, Cambridge, MA 021«9, AIAA Member 1 Downloaded by 47.145.140.97 on December 29, 2021 | http://arc.aiaa.org | DOI: 10.2514/6.2022-2263 AIAA SCITECH 2022 Forum January 3-7, 2022, San Diego, CA & Virtual 10.2514/6.2022-2263 Copyright © 2022 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. AIAA SciTech Forum