ABSTRACT

This research activity deals with 3D printing composites fabricated by Continuous Fiber/Filament Fabrication with an innovative thermoplastic matrix infilled with microcarbon fiber, i.e., Onyx, and carbon reinforcement. Three groups of additively manufactured samples were printed and tested to evaluate the possibility of avoiding the drilling phase to increase the bearing resistance and evaluate the parts’ properties: standard geometry, post-process drilling, and customized geometry. Different configurations were realized for the additively manufactured and drilled samples to assess the reinforcement effect on the bearing performance and identify the 3D printing technology limits. Finally, the customized sample represents a new approach to conceiving a better solution for enhancing the bearing strength. Pin-bearing stress and stiffness have been analyzed through experimental methods, the material compaction quality was detected by ultrasound technique, and failure modes have been discussed. Concerning the additive samples, the bearing strength decreased in all reinforced printed configurations due to the technological limitations of the CFF process. However, exploiting a more flexible approach in the design, a novel bearing configuration with a custom infill strategy was proposed, reaching high values of bearing strength and stiffness. This resulted in a reduction in costs and weight, taking one step toward more sustainable production.

摘要

这项研究活动涉及由连续纤维/长丝制造制造的 3D 打印复合材料，该复合材料具有一种填充有微碳纤维（即 Onyx）和碳增强材料的创新热塑性基体。打印并测试了三组增材制造样品，以评估避免钻孔阶段以增加轴承阻力并评估零件性能的可能性：标准几何形状、后加工钻孔和定制几何形状。对增材制造和钻孔样品实现了不同的配置，以评估增强对轴承性能的影响并确定 3D 打印技术的限制。最后，定制样品代表了一种新方法，可以为提高轴承强度设计更好的解决方案。通过试验方法分析了销轴承的应力和刚度，用超声技术检测了材料的压实质量，并讨论了失效模式。关于添加剂样品，由于 CFF 工艺的技术限制，所有增强印刷配置的承载强度都降低了。然而，在设计中采用更灵活的方法，提出了一种具有定制填充策略的新型轴承配置，达到了轴承强度和刚度的高值。这导致成本和重量的降低，朝着更可持续的生产迈出了一步。由于 CFF 工艺的技术限制，所有增强型印刷配置的承载强度均有所下降。然而，在设计中采用更灵活的方法，提出了一种具有定制填充策略的新型轴承配置，达到了轴承强度和刚度的高值。这导致成本和重量的降低，朝着更可持续的生产迈出了一步。由于 CFF 工艺的技术限制，所有增强型印刷配置的承载强度均有所下降。然而，在设计中采用更灵活的方法，提出了一种具有定制填充策略的新型轴承配置，达到了轴承强度和刚度的高值。这导致成本和重量的降低，朝着更可持续的生产迈出了一步。