Faculty of Mechanical Engineering, Semnan University, Semnan, Iran.
Department of Materials Engineering, Yasouj University, Yasouj, Iran.
PLoS One. 2024 Apr 18;19(4):e0300569. doi: 10.1371/journal.pone.0300569. eCollection 2024.
PLA (Poly-lactic acid)-wood provides more biodegradability through natural fibers, a significant advantage of pure PLA. Nevertheless, these bio-composites may have inferior mechanical properties compared to non-degradable polymer composites, considering the lower strength of natural particles compared to synthetic fibers. This research examines the fatigue behavior of additive-manufactured biopolymer PLA-wood and assesses its comparability with pure PLA. Therefore, solid fatigue test samples were printed using the FDM (fused deposition modeling) method. Afterward, fully reversed rotary bending fatigue experiments were performed at 4 different stress levels (7.5 to 15 MPa) to extract the S-N curve of PLA-wood. Moreover, the fatigue fracture surfaces of the PLA-wood were investigated and compared at the highest and lowest stress levels using an FE-SEM (Field Emission Scanning Electron Microscopy), indicating more ductile fracture marks at higher stress levels. The fatigue lifetime of the PLA-wood decreased by 87.48% at the highest stress level (15 MPa), rather than the result at the lowest stress level (7.5 MPa). Additionally, the results demonstrated that the fatigue characteristics of the printed pure PLA and PLA-wood were comparable, suggesting that the 3D-printed PLA-wood with the used printing parameters can be an alternative choice.
聚乳酸（PLA）-木提供了更多的生物降解性，通过天然纤维，这是纯 PLA 的一个显著优势。然而，与不可降解的聚合物复合材料相比，这些生物复合材料的机械性能可能较差，因为与合成纤维相比，天然颗粒的强度较低。本研究考察了增材制造的生物聚合物 PLA-木的疲劳行为，并评估了其与纯 PLA 的可比性。因此，使用 FDM（熔融沉积建模）方法打印了固体疲劳测试样品。然后，在 4 个不同的应力水平（7.5 至 15 MPa）下进行完全反向旋转弯曲疲劳实验，以提取 PLA-木的 S-N 曲线。此外，使用 FE-SEM（场发射扫描电子显微镜）在最高和最低应力水平下研究和比较了 PLA-木的疲劳断裂表面，表明在较高的应力水平下存在更多的韧性断裂痕迹。在最高应力水平（15 MPa）下，PLA-木的疲劳寿命下降了 87.48%，而不是在最低应力水平（7.5 MPa）下的结果。此外，结果表明，打印纯 PLA 和 PLA-木的疲劳特性相当，表明使用所使用的打印参数的 3D 打印 PLA-木可以是一种替代选择。
