CAREER: Understanding Ultrasonic Processing of Layered Polymer Composites Across Length Scales

这项学院早期职业发展(Career)计划拨款支持有助于理解纤维增强聚合物复合材料超声波加工的研究，从而促进科学进步和振兴美国制造业。与金属等可根据纤维取向和层序定制的传统材料相比，复合材料具有高强度和低重量。某些聚合物复合材料提供了更多的可持续性，因为它们可以在高温下重塑、回收并通过熔融粘合连接在一起。目前的制造技术通常需要高温和昂贵的模具，这限制了热塑性复合材料作为主要结构部件在广泛的行业中的使用。在寻找能源和成本高效的制造和组装技术方面，超声振动处理是一个很有前途的候选方法，它可以在传统方法所需时间的一小部分内实现加固和粘接。这项基础研究进一步推动了复合材料超声加工的发展，推动了航空航天、交通运输、海运、管道和风能行业的几个应用的增长。综合外联计划包括亲身实践活动，以吸引不同人口的K-12女孩，以及通过高级设计项目和技术选修课培训本科生和研究生。这将为复合材料制造业培养一支训练有素的劳动力队伍，从而支持国家的繁荣。在聚合物复合材料中使用超声波加工的挑战，部分原因是由于超快的周期时间和对感兴趣区域的几何限制，很难通过实验捕获发生在界面上的详细过程。这项建议通过阐明工艺-结构-性能的关系并建立新的实验和建模解决方案来应对这些挑战。更具体地说，它将解决两个主要研究目标：1)通过多尺度实验(从分子结构到宏观尺度)了解超声波和材料参数如何控制发热和结晶机制；2)基于实验结果建立多物理有限元模型，以模拟过程和预测键合效率。更好地了解这一过程将允许扩大规模并自信地部署关键应用程序。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This Faculty Early Career Development (CAREER) Program grant supports research contributing to the understanding that underpins the ultrasonic processing of fiber-reinforced polymer composites, promoting both the progress of science and revitalizing the U.S. manufacturing industry. Composite materials possess high strength and low weight, as compared to conventional materials like metals, which can be tailored according to fiber orientation and layer sequence. Certain polymer composites offer further sustainability because they may be reformed at high temperatures, recycled, and joined through fusion bonding. Current manufacturing techniques typically require high temperature and expensive tooling, which limits the use of thermoplastic composites as primary structural components in a wide range of industries. In the search for energy and cost-efficient manufacturing and assembly techniques, processing through ultrasonic vibrations is a promising candidate that can achieve consolidation and bonding in a fraction of the time required by traditional methods. This fundamental research furthers the development of ultrasonic processing of composites, advancing growth of several applications in aerospace, transportation, maritime, piping, and wind energy industries. An integrated outreach plan includes hands-on activities to engage a diverse population of K-12 girls, as well as training of undergraduate and graduate students through senior design projects and technical elective courses. This will result in a highly trained workforce for the composites manufacturing industry and thus, will support national prosperity.The challenges in the use of ultrasonic processing for polymer composites are due, in part, to the difficulty in experimentally capturing the detailed processes of occurring at the interface due to ultra-fast cycle times and geometrical constraints to the region of interest. This proposal addresses those challenges by elucidating processing-structure-performance relationships and establishing novel experimental and modeling solutions. More specifically, it will address two main research objectives: 1) understand how ultrasonic and material parameters govern heat generation and crystallization mechanisms through multiscale experiments (from molecular structure to macro-scale); and 2) establish a multiphysics finite element model based on experimental outcomes to simulate the process and predict bonding efficiency. Achieving greater understanding of this process will allow scale up and confident deployment for critical applications.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.