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

University Of South Carolina At Columbia, Columbia SC

Investigators

Abstract

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.