Workflow for generating, simulating, and optimizing form and toolpath in 3D concrete printing of vaults

Designing for 3D concrete printing presents unique challenges, particularly in vault manufacturing. There is also a lack of design support tools that consider structural performance during printing. This paper proposes a design workflow that includes form and toolpath generation, structural simulation, and optimization. The workflow is implemented on an integrated platform that includes gradient-free constrained optimization. Several objective functions were tested, and results show that the objective function that combines toolpath length and a buildability indicator performs the best. Results also show that fabrication strategy and scale significantly impact vault design, with strategies leading to longer printing times per layer showing notable reductions in overhang angle, volume, and toolpath length. A comparative study between different types of vaults indicated that cloister and squinch vaults displayed the lowest stresses and required the least amount of material. The platform was validated by printing a 1.2 m × 1.2 m cross-vault without formwork.