Fundamental Studies of Process-Material Interactions in Advanced Adhesion-Driven Manufacturing with Automated Placement of Uncured Thermoset Tows as Model Process

自动丝束铺放（ATP）是一种粘合驱动的聚合物基复合材料制造工艺，将一束浸渍树脂的纤维（称为丝束）铺放到工具上或先前铺放的丝束上。该技术广泛应用于航空航天工业，并且由于其提高生产率和减少材料浪费的潜力，在汽车，军事和能源领域也引起了人们的兴趣。ATP工艺需要施加温度和压力，并且工艺条件可能导致已知对复合材料粘合强度有害的缺陷（褶皱、折叠），并且可能导致部件过早失效。该奖项支持对缺陷形成的基础研究，这些研究将实现更好的过程模拟，这将通过为ATP制造过程提供指导来提高复合材料零件的质量。关于工艺-材料相互作用的知识可以显著减少制造缺陷，这应该减少制造周期时间，以及增加制造成本的昂贵且耗时的手动检查。对基本缺陷变形机制的更好理解将有助于开发纤维复合材料的新兴增材制造工艺和用于轻质复合材料结构中具有弯曲路径的复杂几何形状的ATP加工。将作出具体努力，通过南卡罗来纳州的女工程师协会从代表人数不足的群体中招募研究生和本科生。此外，本发明还提供了一种方法，在本研究中开发的ATP制造和过程模拟模块将被纳入复合材料制造课程，为本科生和研究生提供设计和制造的过程-结构-性能联系方面的知识。提高对粘附驱动制造基本原理的理解可以提高零件质量，同时降低与再制造相关的总体成本。修复或再制造有缺陷的部件。 本研究旨在通过调查原位粘结强度-韧性如何发展以及未固化的富含聚合物的材料在接触和粘合过程中如何形成缺陷的基本原理来填补知识空白。特别是，在特征毫秒时间尺度上的时间-温度叠加原理将使用从新颖的凝聚力实验和高速立体数字图像相关中收集的参数来应用。 同时，将开发多物理过程模型，以研究过程参数如何影响缺陷形成，采用数据驱动的机器学习技术来建立无缺陷的过程参数窗口，并为增强的制造过程提供指导。新的基础知识将使无缺陷丝束放置的工艺参数窗口的建立，并将作为一个指南，以提高复合材料部件的质量。这个奖项反映了NSF的法定使命，并已被认为是值得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的支持。

Automated tow placement (ATP) is an adhesion-driven manufacturing process for polymer matrix composites in which a bundle of fibers impregnated with resin—known as a tow—is placed onto a tool or onto a previously-placed tow. The technique is widely used in the aerospace industry and is also gaining interest in automotive, military, and energy sectors due to its potential for improved productivity and reduced material waste. The ATP process requires application of temperature and pressure, and the process conditions can result in defects (wrinkles, folds) that are known to be detrimental to composite bond strength and can lead to premature component failure. This award supports fundamental research into defect formation that will enable better process simulations, which will enhance composite part quality by providing guidelines for the ATP manufacturing process. Knowledge developed regarding process-material interactions can significantly decrease manufacturing defects, which should reduce manufacturing cycle time, as well as expensive and time-intensive manual inspection that increases manufacturing cost. Improved understanding of fundamental defect deformation mechanisms will enable development of emerging additive manufacturing processes for fiber composites and ATP processing for complex geometries with curved paths in lightweight composite structures. A specific effort will be made to recruit graduate and undergraduate students from under-represented groups through the Society for Women Engineers at the University of South Carolina. In addition, a module on ATP manufacturing and process simulations developed in this research will be incorporated into the Composites Manufacturing course for undergraduate and graduate students to provide knowledge on the governing process-structure-property links for design and manufacturing.Improved understanding of the fundamentals of adhesion-driven manufacturing can improve part quality while reducing the overall cost associated with re-work or remanufacturing of defective components. This research aims to fill knowledge gaps by investigating the fundamentals of how in-situ bond strength-toughness develops and how defects form during contact and adhesion of uncured, polymer-rich materials. In particular, the time-temperature superposition principle at characteristic millisecond time scales will be applied using parameters gleaned from novel cohesion experiments and high speed stereo digital image correlation. In parallel, a multi-physics process model will be developed to study how process parameters affect defect formation, with data-driven machine learning techniques employed to establish defect-free process parameter windows and provide guidance for enhanced manufacturing processes. The new fundamental knowledge will enable the establishment of processing parameter windows for defect-free tow placement and will serve as a guide to enhance composite part quality.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.