This research examines the structural performance of Tough Polylactic Acid (PLA) components made through material extrusion, focusing on tensile and fatigue behaviors. Tough PLA, similar to regular PLA, exhibits improved toughness comparable to acrylonitrile butadiene styrene (ABS). As the application of 3D printed parts for functional use expands, understanding the mechanical attributes of materials under both static and dynamic loading conditions is crucial. This study investigates the impact of infill pattern/density and localized reinforcement on the tensile and fatigue strength of Tough PLA samples. Digital image correlation (DIC) and optical micrographs were used to acquire surface-strain data. The findings highlight the influence of localized reinforcement and infill density. Increased infill density is associated with higher tensile strength and Young’s modulus, with specimens at 90 % infill achieving a tensile strength of 28 MPa and Young’s modulus of 0.46 GPa. Incorporating mesh modifiers can enhance tensile properties by up to 20 %. An Analysis of Variance (ANOVA) confirmed the significant effects of these factors on tensile strength. Fatigue test results show a grid pattern without modifiers exhibits the best fatigue life, with specimens enduring up to forty-two thousand cycles at 45 % UTS, while a line modifier balances fatigue strength and tensile properties.

中文翻译：

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研究填充图案和网格改性剂对 3D 打印聚合物疲劳性能的影响


本研究检查了通过材料挤出制成的坚韧聚乳酸 (PLA) 组件的结构性能，重点关注拉伸和疲劳行为。坚韧的 PLA 与普通 PLA 类似，其韧性可与丙烯腈丁二烯苯乙烯 (ABS) 相媲美。随着 3D 打印零件功能性应用的扩展，了解材料在静态和动态负载条件下的机械属性至关重要。本研究调查了填充图案/密度和局部增强对 Tough PLA 样品拉伸和疲劳强度的影响。数字图像相关（DIC）和光学显微照片用于获取表面应变数据。研究结果强调了局部加固和填充密度的影响。填充密度的增加与更高的拉伸强度和杨氏模量相关，填充率为 90% 的样本可实现 28 MPa 的拉伸强度和 0.46 GPa 的杨氏模量。加入网格改性剂可将拉伸性能提高高达 20%。方差分析 (ANOVA) 证实了这些因素对拉伸强度的显着影响。疲劳测试结果显示，不带改性剂的网格图案表现出最佳的疲劳寿命，样本在 45% UTS 下可承受多达 42000 次循环，而线改性剂可平衡疲劳强度和拉伸性能。