Polymer/fibre through-thickness-reinforcement for carbon-fibre reinforced polymer composites

Abstract

Composite materials have, in one form or another, been a fundamental part of humanity’s toolbox throughout its existence. From pre-historic use of natural materials such as wood or bone through to contemporary materials such as reinforced concrete or plywood composite materials throughout history have contributed to shaping the world we live in. In the modern era the term “composite” has become associated with high-performance engineering materials such as glass fibre for shipping or renewable technologies, carbon fibre for automotive or aerospace or even metal/carbon composites used in space exploration. These materials share the common ingredients of a fibrous reinforcement encased in a matrix. Whilst not a defining feature this typically is considered to be a polymer-based material such as epoxy resin. In this work the focus is placed specifically on the laminate structure using layers of carbon fibre and epoxy resin, typically referred to as a “2-D” composite.

The principle aim of this work is to investigate a concept of through-thickness reinforcement that is similar in principle to the traditional metalworking practice of riveting. The concept is that a pin utilising a fibrous reinforcement with a polymer matrix may be placed through the thickness and the ends “flattened” against the part surface using heat and pressure. Once cooled the pins will retain their new deformed shape, anchoring them in position and binding the dry layers of the pre-form together. Once produced such a preform may then be infused with resin to form a completed composite.

There are many questions such a concept raises, such as the efficacy of the reinforcement, the manufacturing parameters, the material choice for the pins, and if there are any other beneficial properties of material produced in this manner. The key objective of this work is to determine if such a concept is worthy of the detailed research needed to fully evaluate and refine this concept into a workable industrial solution.

Date of Award	Mar 2023
Original language	English
Sponsors	Department for the Economy
Supervisor	Alistair McIlhagger (Supervisor) & Edward Archer (Supervisor)