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

这项教师早期职业发展（Career）计划资助的研究有助于理解纤维增强聚合物复合材料的超声波加工，促进科学进步和振兴美国制造业。与金属等传统材料相比，复合材料具有高强度和低重量的特点，可根据纤维取向和层序进行定制。某些聚合物复合材料提供了进一步的可持续性，因为它们可以在高温下重组、回收和通过熔合键连接。目前的制造技术通常需要高温和昂贵的工具，这限制了热塑性复合材料作为主要结构部件在广泛工业中的使用。在寻找能源和经济高效的制造和装配技术的过程中，超声波振动加工是一种很有前途的选择，可以在传统方法所需的一小部分时间内实现固化和粘合。这项基础研究进一步发展了复合材料的超声波加工，促进了在航空航天、交通运输、海事、管道和风能工业中的应用增长。综合推广计划包括实践活动，以吸引不同的K-12女孩群体，以及通过高级设计项目和技术选修课程培训本科生和研究生。这将为复合材料制造业带来训练有素的劳动力，从而支持国家繁荣。在聚合物复合材料中使用超声波加工的挑战部分是由于由于超快的周期时间和感兴趣区域的几何限制，在实验上难以捕捉界面上发生的详细过程。本提案通过阐明处理-结构-性能关系以及建立新的实验和建模解决方案来解决这些挑战。更具体地说，它将解决两个主要的研究目标：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热量产生和结晶机制；2)基于实验结果建立多物理场有限元模型，模拟过程并预测粘接效率。对这个过程有了更深入的了解，就可以对关键应用程序进行扩展和自信的部署。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.