Effects of Fused Deposition Modeling Parameters on the Acoustic Black Hole Termination Efficiency of 3D-Printed Polylactic Acid Tapered Beams

The present study investigates the vibration attenuation characteristics of acoustic black hole (ABH) terminations fabricated entirely from polylactic acid (PLA) using fused deposition modeling (FDM). The ABH concept relies on geometric tapering to decelerate flexural waves, thereby enabling passive vibration reduction. Conventional ABH structures are constrained by fabrication difficulties and reflection effects arising from truncation. In this work, the feasibility of realizing monolithic PLA-based ABH configurations through 3D printing is examined, emphasizing the influence of principal FDM parameters on damping efficiency. The investigation systematically varies layer height, print orientation, and raster angle—the latter defining the infill line direction relative to the principal build axes—to evaluate their combined effects on vibration dissipation and wave reflection. Finite element simulations supported by experimental modal testing show that, despite the limited intrinsic damping of PLA, marked vibration reduction in the 300–3000 Hz range can be achieved through optimized taper geometry and process-aware design. The results confirm the potential of low-cost, single-material ABH structures for practical applications in passive vibration control.