Lightweight C Beam Design & Analysis for Additive Manufacturing

This report presents the design, analysis, and fabrication of a lightweight C‑shaped beam tailored for support‑free fused‑filament fabrication (FFF) in PLA. A 7 in × 4.5 in × 3 in design envelope and a 0.5 kg distributed top load were used to frame a stiffness‑to‑weight optimization problem with a 50 g mass limit. Topology optimization in Altair Inspire was first applied to a solid baseline beam to identify efficient load paths, but the resulting organic geometry was not compatible with extrusion printing constraints (unsupported overhangs and inconsistent features). A manufacturable redesign was then developed in SolidWorks as a triangulated, self‑supporting frame that preserves the optimized load‑carrying architecture. Linear static analysis predicted a maximum deflection of ~0.129 mm and a minimum factor of safety of ~12.5 under the prescribed loading. The final part was sliced in Ultimaker Cura, printed on a Creality Ender‑class printer with 0.2 mm layers and 100% infill, and validated via physical loading with no visible damage. A cost comparison indicates substantial savings versus CNC machining for low‑volume production.