Deposition Strategies for Bar Intersections Using Dot-by-Dot Wire and Arc Additive Manufacturing

Dot-by-dot Wire and Arc Additive Manufacturing (WAAM) is a promising technique for producing large-scale lattice structures, offering significant benefits in terms of deposition rate and material utilization. This study explores strategies for fabricating bar intersections using the dot-by-dot WAAM technology, focusing on creating robust and predictable structures without requiring parameter modifications or real-time monitoring during the deposition. Two different deposition strategies were proposed, that can be, at least geometrically, applied to a general intersection with multiple bars with different angles. In this work such strategies were only experimentally tested on two-bar intersections, assessing their performance in terms of geometrical accuracy, symmetry, and material efficiency. Strategies which utilize layer-by-layer deposition with multiple overlapping dots, called B here, demonstrated the best results in terms of the geometrical features in the intersection zone, assessed by different metrics obtained through an analysis of pictures, such as low asymmetry and high material volume in the intersection zone. In addition, the findings suggest that removing cooling pauses during the deposition of multiple dots on the same layer slightly improves the joint by minimizing excess material buildup. The proposed approach offers a scalable framework for optimizing intersection deposition, paving the way for improved large-scale metal lattice structure manufacturing.