Thermo-structural optimization of density-variable lattice support structures for PBF-LB/M parts and evaluation

Purpose The aim of this study is the development and evaluation of a lattice structure optimization method which delivers density-variable support structures for metal components produced with Laser Beam Powder Bed Fusion (PBF-LB/M). This method combines digital tools and novel approaches to design printable, lightweight support structures for an industrial vane component. The objective of the optimization is to enhance the thermal conductivity and stiffness of the supports while reducing the amount of material used. Design/methodology/approach The boundary value problem (BVP) for the thermo-structural compliance minimization with a mass reduction constraint utilizes the build process simulation. In particular, two methods are investigated: a coupled and a sequential one. Within the optimization the lattice structure properties are modeled in dependence of the lattice volume fraction, a density-like variable, to use existing density-based topology optimization algorithms. The presented method is applied to an exemplary vane component and evaluated at hand of finite element analysis and a trial build job. Findings This paper demonstrates that process simulation results, such as layer end temperatures, provide a valid basis for capturing thermal behavior and enable the sequential optimization of lightweight support structures while ensuring compliance with design constraints. Overall, the optimized support structures significantly reduce material usage while improving thermal management, minimizing distortion, eliminating shrink lines, and enhancing part quality, with gyroid lattices offering superior mass efficiency compared to solid support structures. Originality/value This research presents an enhanced computer aided design method for support structure optimization that satisfy the design for additive manufacturing requirements. By utilizing a novel approach for the fundamental BVP, it is suited for PBF-LB/M parts. The optimized lattice support structures enable high volume reductions, while providing the required conductivity and stiffness.