PSI - Issue 68

Ibrahim T. Teke et al. / Procedia Structural Integrity 68 (2025) 365–371 I. T. Teke & A. H. Ertas / Structural Integrity Procedia 00 (2025) 000–000

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of acetone vapor bath smoothing on the fatigue life of 3D-printed ABS components, finding that the treatment significantly improved fatigue life by reducing surface flaws. Dadashi and Azadi (2023) explored the bending fatigue properties of PLA biomaterials produced using FDM 3D printing, finding that lower extruder temperatures, smaller nozzle diameters, and slower printing speeds generally improve fatigue performance. Yankin et al. (2023) optimized FDM printing parameters for ABS and nylon, discovering that nylon generally outperforms ABS in fatigue life, with the 'tri-hexagon' internal geometry providing the best results. This body of research underscores the critical role of various 3D printing parameters, such as infill density, nozzle diameter, and printing orientation, in determining the fatigue behavior of polymers like PLA, ABS, and nylon. Optimizing these parameters is essential for achieving reliable and durable 3D-printed components. Further investigation is warranted to evaluate the effects of fatigue testing on topology optimization results and refine the mechanical performance of 3D-printed structures. Dadashi and Azadi (2023) also conducted a multi-objective optimization study, balancing mass reduction, fatigue lifetime, and structural performance in 3D-printed PLA cylindrical samples. Raicevic et al. (2023) evaluated the fatigue life of aircraft torque links using numerical simulations, topological optimization, and additive manufacturing, noting that although optimized torque links produced through AM showed reduced mass, they also exhibited a shorter fatigue life due to residual stresses. Even well-established geometric designs can be optimized to achieve significant material cost reductions while maintaining structural integrity, as demonstrated by Teke et al. (2021) and Teke et al. (2024a). These studies show that incorporating additional techniques within hybrid optimization frameworks can effectively enhance both performance and efficiency. The key to success lies in the careful combination of these techniques, where the formation of an optimal geometry is guided by the design requirements. This hybrid approach ensures that the design not only meets functional criteria but also maximizes resource efficiency, which is critical for modern engineering challenges. In the present study, it has been built on this foundation by comparing the newly developed S-D-S-ER method (Teke et al. 2024b) with the conventional D-S-ER method (Teke et al. 2023) using three-point bending fatigue tests. The objective is to explore the potential of the S-D-S-ER method to improve fatigue life and structural performance, offering valuable insights into the future of optimized, cost-efficient design methodologies for a wide range of applications.

2. Material and Methods

The samples, developed by Teke et al. (2024b) using the S-D-S-ER and D-S-ER methods, have been subjected to three-point bending fatigue tests in this study. These samples, whose CAD geometries are shown in Figure 1, were tested within force ranges of 0-1 kN and 0-0.9 kN at a frequency of 10 Hz. The 3D printing parameters for re-PLA are presented in Table 1. For the fatigue tests, the specimens were produced with an infill percentage set to 30%.

Fig. 1. S-D-S-ER model and D-S-ER model.