ElHassan Amged, Ahmed Waleed, Zaneldin Essam
Mechanical and Aerospace Engineering Department, College of Engineering, UAE University, Al Ain P.O. Box 15551, United Arab Emirates.
Engineering Requirements Unit, College of Engineering, UAE University, Al Ain P.O. Box 15551, United Arab Emirates.
Polymers (Basel). 2024 Feb 23;16(5):615. doi: 10.3390/polym16050615.
Using the linear elastic finite element method, we investigated how defects significantly influence the integrity of 3D-printed parts made from biodegradable material by experimental techniques and numerical simulations. A defective flaw was incorporated into the tensile test dog-bone sample using Computer-Aided Design and processed by slicing software. Three distinct raster angles examine two sets of samples, one featuring intact specimens and the other with the introduced defects. An open-source 3D printer was used to fabricate both sets of samples, utilizing biodegradable PLA material. In finite element analysis, we employed a highly detailed model that precisely accounted for the geometry and dimensions of the extruded 3D-printed filament, accurately replicating the actual configuration of the 3D-printed samples to an extent. Our study involved a thorough comparative analysis between the experimental results and the FEA simulations. Our findings uncovered a consistent trend for the intact and defective samples under tensile load. Specifically, in the intact case, the samples with a zero-degree raster orientation presented the highest resistance to failure and displayed minimal elongation. Remarkably, these conclusions paralleled our observations of the defective samples as well. Finite element analysis revealed that the stresses, including Principal, Max shear, and Von Mises, were remarkably higher at the 3D-printed samples' outer surface than the inner layers, reflecting that the failure starts at the outer surface since they exceeded the theoretical values, indicating a significant discrepancy between the simulated and anticipated values.
我们采用线性弹性有限元方法，通过实验技术和数值模拟研究了缺陷如何显著影响由可生物降解材料制成的3D打印部件的完整性。使用计算机辅助设计将缺陷引入拉伸试验狗骨形样品中，并通过切片软件进行处理。三种不同的光栅角度用于检验两组样品，一组为完整试样，另一组为引入缺陷的试样。使用开源3D打印机，利用可生物降解的聚乳酸材料制造这两组样品。在有限元分析中，我们采用了一个高度详细的模型，该模型精确考虑了挤出的3D打印细丝的几何形状和尺寸，在一定程度上准确复制了3D打印样品的实际构型。我们的研究对实验结果和有限元分析模拟进行了全面的对比分析。我们的研究结果揭示了完整和有缺陷样品在拉伸载荷下的一致趋势。具体而言，在完整情况下，光栅取向为零度的样品表现出最高的抗破坏能力，且伸长率最小。值得注意的是，这些结论同样适用于有缺陷的样品。有限元分析表明，3D打印样品外表面的应力，包括主应力、最大剪应力和冯·米塞斯应力，显著高于内层应力，这表明破坏始于外表面，因为它们超过了理论值，表明模拟值与预期值之间存在显著差异。
