Abstract The strength and cracking behaviour under fatigue loading of additively manufactured polylactide (PLA) was investigated experimentally to quantify and model the role of notches. These tests were run under load ratios equal to −1 and to 0. Being supported by the experimental evidence, 3D-printed PLA was treated as a linear-elastic, isotropic, and homogenous material. This allowed the use of the Theory of Critical Distances to be extended also to the fatigue assessment of notched 3D-printed PLA. This theory was seen to return accurate estimates. This confirms that it can be used also to estimate fatigue lifetime of notched 3D-printed polymers.

中文翻译：

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关于增材制造聚乳酸 (PLA) 的缺口疲劳强度

摘要 通过实验研究了增材制造聚乳酸 (PLA) 在疲劳载荷下的强度和开裂行为，以量化和模拟缺口的作用。这些测试在等于 -1 和 0 的负载比下运行。在实验证据的支持下，3D 打印的 PLA 被视为线弹性、各向同性和均质材料。这使得临界距离理论的使用也可以扩展到缺口 3D 打印 PLA 的疲劳评估。这个理论被认为返回了准确的估计。这证实了它也可用于估计带缺口的 3D 打印聚合物的疲劳寿命。