Experimental and Numerical Research of 3D DLP-Printed Solid and Voronoi PLA Resin Specimens Under Tensile and Bending Loads

Additive manufacturing (AM), especially vat photopolymerization processes such as digital light processing (DLP), enables the production of highly detailed and complex geometries with precise material structure control. In this study, the influence of internal structure on the mechanical properties of PLA resin specimens produced using a DLP 3D printer is investigated. Two designs were analyzed: a fully solid structure and a shell with a Voronoi pattern. Tensile and bending tests revealed that solid specimens exhibited higher strength, while Voronoi structures performed better under bending loading despite lower load-bearing capacity due to their porosity ratio. The developed numerical model, analyzed through different numerical simulations using the Ansys 2025R01 Software package and validated by experimental results, showed a strong correlation between experimental and numerical results that confirmed the reliability of the developed models for preliminary design verification. These models hold significant potential for the design of mechanical and biomedical components, including orthopedic immobilization devices. Microscopic analysis revealed brittle fracture in solid specimens with striations and bubble-shaped irregularities, while Voronoi specimens exhibited fragmented surfaces with clean, brittle failure along structural voids. Based on the results obtained, this research demonstrates how additive manufacturing enables the optimization of mechanical properties and material efficiency through precise control of internal structures. In the future, validated numerical models can be used to check the preliminary designs of different components, which will significantly reduce development costs.