Understanding the Fundamental Mechanisms Governing Tensile Strength of High-Performance Small-Scale Carbon/Glass Fibers

了解控制高性能小型碳/玻璃纤维拉伸强度的基本机制

• 批准号: 1915948
• 负责人: Subramani Sockalingam
• 金额: $ 51.16万
• 依托单位: University of South Carolina at Columbia
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1915948&HistoricalAwards=false
• 关键词: Understanding; Fundamental; Mechanisms; Governing; Tensile

This project is jointly funded by the Mechanics of Materials and Structures program and the Established Program to Stimulate Competitive Research (EPSCoR). High performance carbon and glass fibers are widely used as reinforcements in composite material systems for automotive, aerospace and defense applications. The tensile strength of commercial fibers is significantly less than its theoretical limits. The composite systems are often overdesigned, thus any increase in the fiber tensile strength can yield significant cost and weight savings. Modifications of fiber surface treatment (sizing) during manufacturing is a potential route to enhance the fiber strength. Single fiber tensile testing at millimeter-scale is typically used to characterize the effect of sizing on the fiber strength. However, the longitudinal tensile failure of a composite is governed by the fiber strength distribution and defects at microscale lengths. This award supports the fundamental research that overcomes current challenges in characterizing the tensile strength of the fibers at the microscale using experimental and data-driven computational methods. Besides the scientific understanding, this project will also provide a guiding template for the fiber manufacturing process through controlled surface treatment. A direct consequence of improving the tensile strength would be lightweight structures for applications in aerospace, automotive, and sports equipment sectors. As part of this project, a specific effort will also be aimed at recruiting graduate and undergraduate students from under-represented groups through the Society for Women Engineers at the University of South Carolina. Furthermore, the experimental setup developed in this research will be incorporated into a lab course for undergraduate students.A comprehensive understanding of the discrepancy between experimental tensile strength of commercial fibers and its theoretical limits has been elusive, and whether intrinsic fiber strength follows a Weibull statistical distribution remains an open question. This research aims to elucidate the fundamental mechanisms that govern the tensile strength of fibers at microscale gage lengths. Experimental and data-driven techniques will be employed to study the strength distribution of the fibers at microscales. Microscale gage lengths will be accessed by developing a novel in situ transverse loading experiment on single fibers under scanning electron microscope combined with micro-digital image correlation. Data-driven machine learning techniques will be applied to establish the scaling laws of strength. This research will provide new insights into the functional form of the survival probability and strength-controlling mechanisms in fibers influenced by fiber sizing. This new fundamental knowledge of processing (sizing)-structure (defect distribution)-property (tensile strength distribution) relationship at microscale lengths will enable the establishment of scaling laws for strength and will serve as a guide for fiber manufacturing process to enhance the fiber tensile strength.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.

该项目由材料与结构力学项目和已建立的激励竞争性研究项目(EPSCoR)共同资助。高性能碳纤维和玻璃纤维广泛用作汽车、航空航天和国防等复合材料系统的增强材料。商业纤维的拉伸强度明显低于其理论极限。复合材料系统往往设计过度，因此纤维拉伸强度的任何提高都可以显著节省成本和重量。在生产过程中对纤维表面处理(上浆)进行改性是提高纤维强度的一条潜在途径。毫米级的单纤维拉伸测试通常用于表征上浆对纤维强度的影响。然而，复合材料的纵向拉伸破坏是由纤维强度分布和微观长度上的缺陷决定的。该奖项支持基础研究，这些研究克服了目前在使用实验和数据驱动的计算方法在微尺度上表征纤维拉伸强度方面的挑战。除了科学的认识外，该项目还将为通过受控表面处理的纤维制造工艺提供指导模板。提高抗拉强度的直接结果将是航空航天、汽车和运动器材部门应用的轻量化结构。作为该项目的一部分，还将作出具体努力，通过南卡罗来纳大学女工程师协会从任职人数不足的群体中招聘研究生和本科生。此外，这项研究中开发的实验装置将被纳入本科生的实验课程。商业纤维的实验拉伸强度与其理论极限之间的差异一直难以得到全面的理解，内在纤维强度是否服从威布尔统计分布仍然是一个悬而未决的问题。这项研究旨在阐明控制微米级纤维拉伸强度的基本机制。实验和数据驱动技术将被用来研究纤维在微观尺度上的强度分布。通过发展一种新的扫描电子显微镜下的单纤维横向加载实验，结合显微数字图像相关技术，可以获得微尺度的量规长度。将应用数据驱动的机器学习技术来建立强度的标度定律。这项研究将对纤维上浆影响纤维存活概率和强度控制机制的函数形式提供新的见解。这一新的微尺度加工(施胶)-结构(缺陷分布)-性能(拉伸强度分布)关系的基本知识将有助于建立强度的比例定律，并将作为纤维制造工艺的指南，以提高纤维的拉伸强度。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。

项目成果

Sub-microscale speckle pattern creation on single carbon fibers for in-situ DIC experiments

用于原位 DIC 实验的单碳纤维上的亚微米级散斑图案创建

• DOI: 10.12783/asc36/35902
• 发表时间: 2021
• 期刊: Proceedings of the American Society for Composites Technical Conference
• 作者: Shah K, Yang G

Sub-microscale speckle pattern creation on single carbon fibers for scanning electron microscope-digital image correlation (SEM-DIC) experiments

• DOI: 10.1016/j.compositesa.2022.107331
• 发表时间: 2022-11
• 期刊: Composites Part A: Applied Science and Manufacturing
• 作者: Karan Shah;S. Sockalingam;H. O'Brien;G. Yang;Mohammad El Loubani;Dongkyu Lee;M. Sutton