Optimum design of steered-tow composite structures via characterization of automated fibre placement induced defects

自动纤维贴装(AFP)是一种制造复杂几何形状复合材料结构的先进技术。波音、空客和其他世界领先的飞机制造商最近开始将这一工艺用于航空产品，因为它的自动化制造能力减少了人工劳动，提高了产品质量，并降低了最终成本。与其他复合材料制造工艺相比，AFP允许沿着曲线路径自由引导纤维丝束方向，控制丝束速度，并在复杂的结构几何形状中空间放置所需数量的纤维。这导致了结构性能的增强和重量的减轻。尽管这些改进是有希望的，但目前有两个关键因素阻碍了AFP潜力的实现。第一个是随着缺陷的形成而出现的制造问题，这些缺陷对最终产品的机械性能产生了未知的影响。第二个问题是设计问题，包括利用导向光纤的能力来优化结构性能。该项目旨在表征工艺引起的缺陷对机械性能的影响，最终目的是确定优化的导向纤维路径，并将不良的有害缺陷降至最低。这项工作需要a)复合材料表征、b)失效分析和预测模型、c)多尺度建模和结构优化以及d)关于AFP过程的技术诀窍的互补专业知识相互交织。研究小组的每个成员将提供所需的能力：a)来自蒙特利尔理工大学；b)来自麦吉尔大学；d)来自NRC-IAR和工业合作伙伴(庞巴迪航空航天公司和综合大西洋公司)。该项目的预期成果既具有科学性，又具有经济性。首先是知识贡献，这将使工业合作伙伴成为加拿大法新社制造业的领导者，正如他们计划的那样。二是新增知识对加拿大经济的影响，特别是对航空业的影响。参与这项合作研究的几名学生将发展行业合作伙伴正在寻找的技能。

Automatic Fiber Placement (AFP) is an advanced technology for manufacturing composite structures of complex geometry. Boeing, Airbus and other world leading aircraft manufacturers have recently started to use this process for aviation products because its capability of automated fabrication reduces manual labour, improves product quality and cuts the final cost. Compared to other composite manufacturing processes, AFP gives the freedom of steering fiber-tow orientations along curvilinear paths, controlling the tow speed and spatially placing the required number of fibers throughout a complex structural geometry. This results in enhanced structural performance and reduced weight. Although these improvements are promising, two key factors currently hinder the fulfillment of AFP potential. The first is a manufacturing issue that emerges with the formation of defects with unknown impact on the mechanical properties of the final product. The second is a design matter, which consists of the exploitation of the steering fiber capabilities to optimize the structural performance. This project aims at the characterization of the impact of process-induced defects on the mechanical properties with the final aim of defining optimized steered fiber paths and minimizing undesirable detrimental defects. The work requires the intertwining of complementary expertise from a) composite material characterization, b) failure analysis and prediction models, c) multiscale modelling and structural optimization, as well as d) know-how about the AFP process. Each member of the research team will provide a required competence: a) from École Polytechnique de Montréal; b) and c) from McGill University, d) from NRC-IAR and the industrial partners (Bombardier Aerospace and Composite Atlantic). The expected outcomes of this project are both scientific and economic. The first is knowledge contribution that will allow the industrial partners to be the Canadian leaders in AFP manufacturing, as they plan to be. The second is the impact of the added knowledge on the Canadian economy, especially for the aircraft industry. Several students involved in this collaborative research will develop skills that the industrial partners are looking for.