Commonly used 3D printed samples are partially infilled to reduce time and cost of printing, with mechanical properties dependent on the infill. In this work, the influence of the percentage and pattern of infill in PLA printed samples on the elastic modulus and characteristic stresses was analyzed. The elastic modulus, E , and characteristic stresses ( σ 0.2 , σ 4 and the maximum tensile stress) were determined for each sample using impulse excitation technique, IET, and uniaxial tensile tests. An apparent density was calculated for each pattern and infill percentage, and the mechanical parameters were studied as a function of such density. The results of IET obtained in different modes of vibration were analyzed and an apparent value of E was calculated. FEM simulations were carried out and the results were compared with the experimental ones. The mechanical properties for different infill percentages and infill patterns were studied by comparing the specific values of E and the stresses. Samples with higher infill percentages exhibit the best specific values of maximum stress and E , but the sample with 20% infill has the highest specific yield stress and a good value of the specific E from flexural vibrations.

中文翻译：

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制造参数对通过熔融沉积建模技术生产的 3D 打印 PLA 样品的弹性模量和特征应力的影响

常用的 3D 打印样品部分填充以减少打印时间和成本，机械性能取决于填充物。在这项工作中，分析了 PLA 印刷样品中填充的百分比和图案对弹性模量和特征应力的影响。使用脉冲激励技术、IET 和单轴拉伸试验确定每个样品的弹性模量 E 和特征应力（σ 0.2 、σ 4 和最大拉伸应力）。计算每个图案和填充百分比的表观密度，并研究机械参数作为这种密度的函数。分析了在不同振动模式下获得的 IET 结果，并计算了 E 的表观值。进行了有限元模拟，并将结果与​​实验结果进行了比较。通过比较 E 的特定值和应力，研究了不同填充百分比和填充模式的机械性能。填充百分比较高的样品表现出最大应力和 E 的最佳比值，但填充 20% 的样品具有最高的比屈服应力和良好的弯曲振动比 E 值。