This study investigates the mechanical behavior of six triply periodic minimal surface (TPMS) structures—gyroid, primitive, diamond, lidinoid, neovious, and splitP—fabricated using stereolithography (SLA) 3D printing with a tough engineering resin. Each structure measures 70x70x70 mm³ and maintains 75% porosity, designed to enhance properties like lightweighting and energy absorption. The resin’s excellent mechanical properties make it suitable for engineering prototypes, mechanical aids, fixtures and medical devices.
Compression tests were conducted at a deformation rate of 2 mm/min to compare the mechanical response of the TPMS structures. Results indicate that, within the same strain range, stress ascends in the elastic zone in the following order: lidinoid, primitive, neovious, splitP, diamond, and gyroid. This sequence highlights the varying mechanical responses under identical testing conditions. While porosity and dimensions remained constant, most structures followed a clear trend where thicker walls resulted in higher stress in the elastic zone. However, neovious, despite having the thinnest walls (0.31 mm), performed unexpectedly well, ranking fourth in stress, surpassing some thicker structures. The wall thickness for other structures ranged from lidinoid (1.17 mm), splitP (1.33 mm), diamond (1.94 mm), primitive (1.31 mm), to gyroid (2.32 mm). The splitP and diamond structures displayed very similar stress-strain behavior, as reflected in their close curves on the stress-strain diagram.
These findings emphasize that while thicker walls generally correlate with increased stress, the geometry of the TPMS structures plays a significant role in mechanical behavior. The unique performance of neovious further underscores that wall thickness alone cannot predict mechanical outcomes. By leveraging advanced TPMS designs and tough resin, this study demonstrates the potential for creating lightweight, robust components for various engineering and medical applications, enhancing stress distribution, energy absorption, and overall mechanical performance.
