Nanoscale Design of Interfacial Kinematics in Composite Manufacturing

聚合物基复合材料在航空航天、汽车和其他应用中的普遍使用需要对制造工艺和新颖的设计策略有基本的了解，以设计其行为。铺层界面在复合材料制造中起着至关重要的作用。固化过程中层板界面的移动可能导致影响复合材料结构性能的制造缺陷，并且在一些应用中是限制因素，导致飞机和民用基础设施等产品的延迟和重新设计。该补助金旨在通过开发一种使用数字图像相关（DIC）的新型原位表征方法，了解复合材料界面在制造过程中的演变和运动。此外，纳米级的界面组分，如氧化锌（ZnO）纳米线将被用来机械地改变固化过程中的界面行为。多尺度计算模型将补充实验研究。这项研究的结果将导致新的诊断，减少加工引起的缺陷，并解决商业和国防工业目前的制造需求。该项目的教育影响包括开发一个垂直整合的途径，让学生参与材料工程，从K-12到研究生院。这项研究将阐明界面运动学和能量学在制造过程中复合材料结构层间界面演变中的作用。研究小组将开发一种新的实验方法，用于复合材料加工过程中表面和界面变形的原位表征，利用定制的商业复合材料高压釜与数字图像相关系统。表面应变和位移测量将与非原位X射线断层扫描和热表征相结合，以绘制界面热机械响应作为设计和加工参数的函数。此外，界面行为将通过ZnO纳米线在碳纤维上的快速和受控生长来设计，以创建纳米级界面组件，该组件增加了纤维的抗弯曲性，并在界面处产生联锁效应，以减轻缺陷传播。实验研究将通过无定形聚合物界面滑动的分子动力学模拟和多孔介质中流动的介观模拟来补充。这一综合性的原位表征、界面设计和建模方法将使人们对复合材料制造过程中的铺层运动有一个基本的了解，并开发出减少加工引起的缺陷的方法。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

The ubiquitous usage of polymer matrix composites in aerospace, automotive, and other applications necessitates both a fundamental understanding of the manufacturing process and novel design strategies to engineer their behavior. Ply interfaces are known to play a crucial role in composite manufacturing. Movement of ply interfaces during curing can lead to manufacturing defects that affect the composite structure performance and have been a limiting factor in several applications, resulting in delays and redesigns of products like aircraft and civil infrastructure. This grant aims at understanding the evolution and movement of composite interfaces during their manufacturing through the development of a novel in-situ characterization approach using digital image correlation (DIC). In addition, nanoscale interfacial components such as zinc oxide (ZnO) nanowires will be utilized to mechanically alter the interfacial behavior during curing. Multiscale computational modeling will complement experimental investigations. The outcome of this research will lead to novel diagnostics that reduce processing-induced defects and addresses the current manufacturing needs of the commercial and defense industries. The educational impacts of the project involve the development of a vertically integrated pathway for engaging students in materials engineering, all the way from K-12 to graduate school.This research will elucidate the role of interfacial kinematics and energetics in the evolution of inter-ply interfaces in composite structures during manufacturing. The research team will develop a novel experimental method for in-situ characterization of surface and interface deformations during composite processing, utilizing a customized commercial composite autoclave with a digital image correlation system. The surface strain and displacement measurements will be combined with ex-situ X-ray tomography and thermal characterization to map the interfacial thermomechanical response as a function of design and processing parameters. Additionally, the interfacial behavior will be engineered through the rapid and controlled growth of ZnO nanowires on carbon fibers to create a nanoscale interfacial component that increases the fiber bending resistance and creates an interlocking effect at the interfaces to mitigate defects propagation. The experimental research will be complemented by molecular dynamics simulations of the sliding of amorphous polymer interfaces and mesoscale simulation of flow in porous media. This comprehensive approach of in-situ characterization, interface design, and modeling will lead to a fundamental understanding of the ply movement during composite manufacturing and development of methods to reduce the occurrence of processing-induced defects.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.