Manufacturing Technology: Composites Fibres

This flashcard set covers the fundamental concepts of composite fibre manufacturing, including drafting standards, orientation control, drape properties, and modeling techniques.

Drafting Standards

The identification of ply details including ply number, unique material identifier, edge positions, and fibre orientation based on surface geometry.

Ply number

A drafting identifier that generally works from the tool face outward.

Unique material identifier

A label for each ply covering factors such as fibre, matrix, reinforcement type, and thickness.

Fibre orientation identifier

A drawing element used to capture detail and control the orientation of fibres within a specific ply.

$0^{\circ}$ direction

A nominal direction included on composite drawings, generally drawn at a convenient point rather than being locked to a specific tool datum.

Drape

The property or study of reinforcement deformation and the changes in fibre angles that occur when ply elements are shaped to a tool.

Compressive stress

The stress built up on the inside of a radius when taking a tow around a corner, causing the tow to buckle or wrinkle.

Short fibres

Reinforcements that can be stretched along and across the fibre direction and sheared, providing maximum formability and allowing local embossing.

Continuous aligned fibres

Reinforcements that can be stretched only across the fibre direction and can be sheared, offering good theoretical formability but no embossing.

Woven continuous fibre cloth

Reinforcement that cannot be stretched along or across the fibre direction and can only be sheared as if pinned at tow cross-over points.

Hand lay-up

The dominant manufacturing process for which woven cloth is widely used because of its excellent practical handling and reversible behavior.

Kinematic models

Simple computer models that predict how cloth geometry maps to surface geometry, often describing cloth as a cell of rigid bars with rotation about hinges.

FE based approach

A modeling method that includes out-of-plane effects and tool interactions, often requiring significant materials data and processing time.

Virtual Fabric Placement software

Modeling software that runs in real time, performing as quickly as fabric can be draped in practice compared to traditional FEA simulations.

$V_f$ (Fibre Volume Fraction)

The ratio of fibre volume to total volume, which increases as pressure is applied and thickness reduces during consolidation.

Bridging

A defect that occurs during consolidation specifically on an internal radius.

Fibre wrinkling

A defect that can lead to structural issues, often occurring during consolidation on an external radius.

Automated cutting

The production process of using computer software to optimize patterns and cut reinforcements, replacing manual cutting with knives and templates.