Advanced Continuous Tow Shearing Utilising Tow Width Control

Abstract

This doctoral study introduces the next generation of Continuous Tow Shearing (CTS), featuring
an innovative on-the-fly Tow Width Control (TWiC) concept integrated into the existing CTS process.
While the CTS process has been successful in effectively mitigating fibre-steering-induced defects in
1D angle variation layups through in-plane shear deformation of the tow, it has exhibited limitations
when applied to more complex-shaped layups. Similar to the Automated Fibre Placement (AFP)
method, CTS utilises finite-width tows, which may result in geometry-induced defects such as gaps,
overlaps, or fibre discontinuities with resin-rich areas.
Implementing the novel TWiC concept in conjunction with in-plane shear deformation of the tow
unlocks the potential to eliminate typical steering- and geometry-induced layup defects, allowing for
highly efficient, defect-free fibre steering over complex-shaped surfaces.
A prototype of this Advanced CTS (ACTS) method was developed and subsequently subjected to trials.
Various layups featuring challenging fibre paths were manufactured and analysed, assessing the
accuracy and feasibility of the integrated TWiC system.
The results demonstrated a significant enhancement in layup quality compared to AFP and current
CTS techniques. Additionally, the TWiC module was employed to trial a novel layup technique
designed to produce high global fibre angles by reducing local shear angles. This approach showed
significant improvements in global shift-width accuracy compared to existing literature.
Overall, incorporating the innovative TWiC concept improved the layup quality and accuracy
compared to AFP and CTS, showing great potential to enhance current composite manufacturing
techniques.

Date of Award	23 Jan 2024
Original language	English
Awarding Institution	University of Bristol
Supervisor	Byung Chul (Eric) Kim (Supervisor) & Dmitry Ivanov (Supervisor)