CAREER: Mechanical Behavior of Graphene-Carbon Fiber Composites

This Faculty Early Career Development (CAREER) Program grant will develop the fundamental science for the design and characterization a new family of damage-tolerant composite materials that are strong, stiff, and ductile. Carbon fiber reinforced polymer-matrix composites are currently considered state-of-the-art for defense, energy, and transportation applications. These polymer-matrix composites, however, suffer several limitations, including brittle fracture and poor damage tolerance, both of which result in catastrophic failures in composite structures. The novel composites, based on graphene within a carbon fiber matrix, address major shortcomings of traditional polymer-matrix alternatives such as the lack of ductility and the propensity to damage and therefore has the potential to help save billions of dollars in failure and inspection costs across multiple industries on an annual basis. The polymer-free nature of the graphene-carbon fiber (matrix) composite will enable resistance to high impact energy, electromagnetic interference (EMI), high temperatures, and harsh environments. These multifunctional aspects will significantly reduce cost and design complexity and can potentially result in the manufacturing of safer and more durable structures for defense, energy, and transportation applications. This project will also result in effective platforms to attract and train students in this emerging field and has the increasing enrollment in Mechanical Engineering at the University of New Mexico, specifically women. The grant also supports activities directed at increasing the interest in STEM education in the local community among ethnic minorities including Native American college students and Hispanic K-12 students. This project will investigate and elucidate the underlying mechanisms that can be used to control and tailor the ductility and damage progression in carbonaceous nanocomposites, specifically in graphene-carbon fiber composites. Graphene-based materials have been extensively studied recently, mainly by incorporating trial and error approaches, to optimize their mechanical properties rather than effectively studying to understand the underlying mechanisms. These studies have shown promising results but cannot be used to tailor mechanical properties due to the vast design parameter space available to graphene-based materials. This project utilizes a combined numerical modeling and state-of-the-art multi-scale characterization approach to understand and tailor mechanical properties in the graphene-carbon fiber (matrix) composites. The research objectives include the understanding of the stress-transfer mechanisms at the graphene-carbon fiber interface and elucidation of the underlying failure mechanisms in these composites. These resolution of these underlying mechanisms will answer some of the long-standing scientific questions and challenges regarding the strength-ductility trade-off in nanocomposites. 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.