Adaptive slicing and trajectory development for improved precision in WAAM produced parts for civil construction

The adoption of Additive Manufacturing (AM) in construction is increasing yet concerns about cost and environmental impact remain significant. Hybridization of structural components offers a promising solution, applying AM only in regions requiring complex geometries or enhanced performance, while conventional manufacturing is retained elsewhere. Directed energy deposition (DED) processes are suited to this approach, enabling intricate geometries with higher strength, reduced weight, and longer service life. For large steel structures, wire arc additive manufacturing (WAAM) is attractive for high deposition rates and compatibility with construction environments, with less stringent safety requirements than laser-based DED. A key challenge in hybrid manufacturing is creating reliable transition zones connecting AM components to conventional elements. These zones often require complex deposition trajectories beyond standard slicing and path planning. This study introduces an adaptive slicing and path planning strategy to improve geometric precision in WAAM components for hybrid applications. A novel deposition method is demonstrated for fabricating a variable-thickness high-strength low-alloy (HSLA) steel transition piece on a circular hollow section (CHS) tube, 107 mm in diameter with a 3.6 mm wall thickness. The slicing algorithm uses experimentally derived regression models linking deposit track geometry with wire feed rate (WFR) and travel speed (TS), enabling automated, layer-specific toolpath adjustments. The method is validated through 100 mm multilayer variable thickness wall depositions. Evaluations of geometric accuracy, deposition stability, and key performance indicators show it improves deposition consistency and dimensional fidelity. These findings support the development of robust WAAM-based strategies for producing precise and efficient transition zones in hybrid steel structures.