Form-Finding of the Metal 3D-Printed Node with Complex Geometry

The application of additive manufacturing (AM) technology in architecture and structural engineering has been extended due to recent development of metal 3d printing. One of the most common structures namely, space frame consists of a set of bars that is configured in three dimensions, with bars connected by nodes. This article presents two methods to design 3d-printed nodes to accommodate any number of incident bars at arbitrary angles. A multi-branch node is sketched using the dimensional information of the blank space between the converging bars in a pre-designed space frame and then parameterized by two different approaches to perform structural optimization. The optimization procedure is accomplished using a genetic algorithm to minimize the maximum von Mises stress as the objective function subjected to the mass of the node as a constraint function. Finally, functional tests are conducted on 3D printed metal nodes in order to compare the strength and stiffness of the nodes designed by the two form-finding approaches.