Multi-fidelity structural design for 3D concrete printing with selective paste intrusion

This paper presents a method for the structural design of additively manufactured concrete structures using the Selective Paste Intrusion (SPI) technique. The approach addresses the specific constraints of 3D printing while leveraging its unique design potential. The proposed method integrates global geometry generation, segmentation into manufacturable components, detailed structural design, and advanced analysis. A multi-fidelity modeling strategy connects low-fidelity models, such as strut-and-tie networks for force path generation, with high-fidelity models that use continuous geometries and stress fields for precise design refinement. Low-fidelity models, developed through Vector-based Graphic Statics and Combinatorial Equilibrium Modeling, facilitate rapid design exploration during the early design phase, whereas high-fidelity models enable advanced design development through finite element simulations and optimization techniques. Segmentation is guided by force flow to enhance manufacturability and ensure normal stress transmission at joints. The proposed method is demonstrated through a case study of a 3D-printed segmented pedestrian bridge manufactured with the SPI technique, highlighting its effectiveness in optimizing structural performance, ensuring stability, and accommodating printing constraints from the initial design phase.