This research project investigates the application of a multi-fidelity structural design workflow for designing complex 3D printed structures using a novel powder bed printing technique called Selective Paste Intrusion (SPI). In this context, the workflow combines Vector-Based Graphical Statics and Finite Element Method (FEM) for global shape-finding of 3D printed structures, exploiting the strengths of both approaches, such as speed and accuracy. In this combined manner, different levels of complexity are addressed simultaneously, thus being referred to as multi-fidelity design.

Given the constraints and opportunities unique to the SPI technique, the developed structure design workflow has been applied to the design of a 1:1 demonstrator. The resulting design is a 3D-printed concrete bridge consisting of 21 parts that are dry-jointed and held in place by the structural arrangement of the parts and the geometric formulation of the joints. To increase structural robustness and redundancy against unforeseen loads, the bridge design incorporates two post-tensioning cables running laterally within the concrete elements. The 3D-printed concrete bridge is supported by two steel frames with diagonally placed horizontal tension cables that provide horizontal stability to the structure.

The design concept of the 3D-printed concrete pedestrian bridge 'Bridge the Gap' was initially developed by a group of architecture students (Y. Cai, A. Rasmussen, P. Schneider) as part of a design studio project at the Technical University of Munich under the supervision of Prof. Dr. P. D’Acunto (Professorship of Structural Design) and Prof. Dr. K. Dörfler (Professorship of Digital Fabrication). Based on this initial concept, a full-scale prototype of a 5-meter-span bridge was structurally designed, engineered, and manufactured as a joint research collaboration between current and prospective PIs of the AMC TRR277.