The impact of defects on the mechanical performance of fiber reinforced composites manufacutured using 3-D printing

3D打印已成为工业4.0（智能虚拟数字工厂）中的一项重要技术，现在在航空航天领域更加普及。目前，空客和波音主要使用由金属材料制成的3D打印部件，这些部件的材料和结构特性都经过分析、测试和验证。然而，3D打印中不同材料的使用将会增加和普及，特别是纤维增强复合材料，可以使用流行的机器，如熔融沉积成型（FDM）。3D打印和纤维增强复合材料的结合可以通过引入负载导向设计来实现更轻的结构。因此，在未来十年内，将从3D打印金属零件向3D打印复合材料产品发生重大转变。自60年代以来，在从金属部件到使用传统制造技术制造的复合材料产品的转变中也观察到了同样的趋势。 这项研究的长期目标是确保加拿大成为纤维增强复合材料3D打印的世界领导者，加拿大公司在制造低成本和高性能功能部件方面获得竞争优势。目前，有几个知识差距阻碍了复合材料在不同行业的3D打印中的广泛使用： 复合材料3D打印过程中出现的缺陷是工艺中固有的，也可能源于设计和/或零件几何形状。故障机制没有得到很好的研究和有效的模拟技术是不可用的缺陷的影响进行评估。 3D打印的负载导向设计概念尚未建立，目前设计人员仅允许在制造过程中选择每层内的预定纤维路径（主要是直纤维）。 关于3D打印复合材料零件的机械特性的数据非常有限，特别是缺陷对最终零件结构性能的影响是未知的。 该研究计划旨在解决上述知识差距，并有三个短期目标： 1.开发虚拟仿真工具，分析缺陷对3D打印复合材料零件机械性能的影响。 2.开发优化工具，以找到最佳纤维路径，从而改善3D打印复合材料部件的结构性能。 3.对3D打印的复合材料试样和演示器进行机械测试，并验证上述模拟和优化工具。 虚拟仿真和优化工具，特别是3D打印工具，为关键新兴技术带来了巨大的好处。这为加拿大制造商和工业产品公司创造了巨大的机会。他们将能够设计高效的产品，提高设计生产力，减少浪费，降低成本，缩短上市时间。

3D printing has become an important technology in Industry 4.0 (smart-virtual-digital factory) and is now more pervasive in aerospace. Currently, Airbus and Boeing use mainly 3D printed parts made from metallic materials, whose material and structural properties are analyzed, tested, and validated. However, there will be an increase and spread to the use of different materials in 3D printing, especially fiber reinforced composites, that can be accommodated using popular machines, like Fused Deposition Modeling (FDM). The combination of 3D printing and fiber reinforced composites can lead to lighter structures through the introduction of load-oriented designs. As a result, there will be a major shift from 3D printed metal parts towards 3D printed composite products over the next decade. The same trend has been observed since the 60s in the move from metallic parts to composite products manufactured using conventional fabrication techniques. The long term objective of this research is to ensure that Canada becomes a world leader in 3D printing of fiber reinforced composites and Canadian companies gain a competitive edge for manufacturing low cost and high performance functional parts. Currently, there are several knowledge gaps that prevent the widespread use of composites in 3D printing in different industries: Defects emerge during composites 3D printing that are inherent in the process and can also stem from design and/or part geometry. The failure mechanism is not well studied and efficient simulation techniques are not available to evaluate the impact of defects. Load-oriented design concept is not well established for 3D printing and currently designers are only allowed to select predetermined fiber paths (mostly straight fibers) within each layer during manufacturing. There is very limited data on mechanical characterization of 3D printed composite parts, especially the impact of defects on the structural performance of the final parts is unknown. This research program is aimed at addressing the above knowledge gaps and has three short term objectives: 1. Developing a virtual simulation tool to analyze the impact of defects on mechanical performance of 3D printed composite parts. 2. Developing an optimization tool to find optimum fiber paths for improved structural performance of 3D printed composite parts. 3. Performing mechanical tests on 3D printed composite specimens and demonstrators, and validating the above simulation and optimization tools. Virtual simulation and optimization tools, especially for 3D printing, deliver significant benefits to key emerging technologies. This creates tremendous opportunities for Canadian manufacturers and industrial product companies. They will be able to design efficient products, increase design productivity, and reduce waste, cost, and time-to-market.