Design and Manufacture of Structural Composites provides an overview of the main manufacturing challenges encountered when processing fibre-reinforced composite materials. Composites are unique in that the material is created at the same time as the structure, forming a very close link between the constituents, the manufacturing process and the resulting mechanical performance. This book takes an in-depth look at material choices and the intermediate steps required to convert different fibre and matrix combinations into finished products. It provides an insight into recent developments for each of the manufacturing processes covered, addressing design, cost, rate and mechanical performance.
Topics covered include an introduction to composite materials, material preforming and conversion, moulding, digital design and sustainability, which addresses waste reduction, disassembly and fibre recovery. This book has been developed primarily as a teaching resource with contributions from leading experts in the field. The content has evolved from courses given by the authors to mechanical engineering and materials science students, at both undergraduate and postgraduate levels. It also draws upon experience gained during research projects and from leading industry experts. It therefore provides non-specialists with a valuable introduction to composite manufacturing techniques, helping to determine the most suitable manufacturing routes and to understand the challenges associated with the production of high-performance composite components.
Author(s): Lee Harper, Mike Clifford
Series: Woodhead Publishing Series in Composites Science and Engineering
Publisher: Woodhead Publishing
Year: 2022
Language: English
Pages: 555
City: Cambridge
Design and Manufacture of Structural Composites
Copyright
Contributors
Preface
Introduction
What is a composite?
Composites manufacturing
Where is the industry heading?
Automation
Sustainability
Challenges
Aerospace
Renewable energy
Energy storage
Automotive
Summary
References
Reinforcing fibres
Introduction
Types of fibre reinforcement
Inorganic fibres
Glass fibre
Basalt fibre
Ceramic fibres
Organic fibres
Carbon (graphitic) fibre
Aramid fibre
Natural (cellulosic) fibres
Other polymer fibres
Fibre coatings
Fibre forms, nomenclature, properties, and testing
Finished fibre forms
Textile materials
Discontinuous fabrics
Properties and testing
Sustainability, recycling, and reuse
Summary
References
Resins for structural composites
Introduction
Thermosetting resins
Epoxy
Epoxy chemical structures
Epoxy cure mechanism
Epoxy curing agent selection
Epoxy resin selection
Bio-derived epoxies
Recyclable epoxies
Powder epoxy
Unsaturated polyester
Vinyl ester
Benzoxazine
Bismaleimide
Toughened thermosets
Thermoplastic resin systems
PEEK and PEKK
Chemical structure
Crystallisation and morphology
Anionic polyamide 6 (APA6)
Liquid acrylic resins
Resin characterisation
Rheometry
Differential scanning calorimetry
Dynamic mechanical analysis
Property comparison of resins
Summary
Acknowledgements
References
Intermediate composite materials
Introduction
Dry intermediate materials
Dry fibre architectures
Tow handling and spreading
Continuous fibre architectures
Woven textiles
Non-crimp fabrics
3D fabrics
Discontinuous fibres architectures
Unifilo/chopped strand mat
Thermoset matrix composite intermediates
Preimpregnated reinforcements
Thermoset prepreg manufacturing process
Thermoset moulding compound manufacturing process
Recent developments in thermoset prepregs
Thermoplastic matrix composite intermediates
Thermoplastic matrix classes and final applications
Tape thermoplastic matrix intermediates
Comingled fibre thermoplastic matrix intermediates
Powder thermoplastic matrix intermediates
Cores
References
Two-dimensional to three-dimensional dry fibre preforming
Introduction
Fabric materials for preforming
Choice of commercial fabrics
Formability mechanisms
In-plane shear
In-plane tension
Out-of-plane bending
Material sliding
Fabric forming techniques
Press tool forming
Diaphragm forming
Single vs double diaphragm forming
Forming-induced defects
Press tool forming defects
Diaphragm forming defects
Scenarios for defect mitigation
Summary
References
Automated fibre placement
Introduction
History and development of the automated tape laying and automated fibre placement processes
Current status of processes
Basic principles of operation, gantry versus robot designs
Thermoset matrix processing
Thermoplastic matrix processing
Current challenges
Productivity issues
Accuracy and control issues
Temperature control and heating strategies
Lay-up head design and operational issues
Impacts on cured ply thickness and as-laid quality
Monitoring and control
Next-generation AFP/ATL
Advantages and limitations of AFP and ATL
Steering effects and tack
Dry fibre AFP issues
Tailored blanks and post-forming
Development areas and future research
References
Braiding and filament winding
Introduction
Braiding
2D braiding
3D braiding
Braid parameters
Braid angle
Cover factor
Interlacement pattern
Nesting factor
Fibre tension
Braid design tools
Braid manufacturing challenges
Filament winding
Conventional filament winding
Multifilament winding
Multi-supply filament winding (MFW)
3D filament winding (3DFW)
Multifilament winding with through-thickness reinforcement
Toroidal winding
Filament winding challenges
Hybrid braid-winding
Structural performance of braided and filament-wound composites
Braiding
Filament winding
Braid-winding
Summary
References
Three-dimensional woven composites
Introduction
Definition, classification, and motivation of 3D woven preforms
Definition
Classification of 3D woven preforms
Motivation for 3D woven preforms
Manufacturing of 3D woven preforms
Influence of microstructural parameters on defects in 3D woven composites
Performance and failure mechanisms of 3D woven composites
Tensile performance
Compressive performance
Impact performance
Machine developments for 3D woven composites
Summary
References
Autoclave and out-of-autoclave processing of prepregs
Introduction
Prepreg processing
Consumables
Curing equipment and tooling
Prepreg materials
Prepreg fibre bed properties
Fibre bed compaction
Fibre bed permeability
Air permeability
Prepreg bulk factor
Prepreg degree of impregnation
Prepreg resin properties
Prepreg cure kinetics
Prepreg rheological behaviour
Volumetric changes
Resin elastic modulus
Process design
Air evacuation
Cure cycle selection
Challenges
Sandwich panels
Complex shaped parts
Summary
References
Liquid composite moulding
Introduction
Theory
Process cycle
Resin flow
Resin cure
Heat transfer
Inter-dependencies
Solution for the resin flow problem
Processing properties of reinforcement
Reinforcement types
Permeability
Basics of permeability
General comments on permeability
Practical problems
Compaction response
Processing properties of matrix
Thermoset matrix
Thermoplastic matrix
Implementation
Practical considerations
Process variants
Resin transfer moulding
High-pressure resin transfer moulding
Vacuum infusion
Light RTM
Compression RTM
Sandwich structures
Summary
References
Compression moulding
Introduction
Overview of compression moulded composite materials and their associated processing routes
Sheet moulding compounds (SMCs)
Constituents
Fabrication of SMCs
SMC compression moulding process
Glass mat thermoplastics (GMTs)
Constituents
Fabrication of GMTs
GMT compression moulding process
Long fibre thermoplastics (LFTs)
Platelet and scrap materials
Compression moulding challenges
Consolidation and flow phenomena during compression moulding
Flow-induced fibre microstructures
Flow-induced pore evolution during compression moulding
Current trends and outlook
References
Thermoplastic stamp forming
Thermoplastic forming processes and process windows
Materials and deformation mechanisms
Material characterisation
Process modelling and sensitivity analysis
Forming-induced defects
Design for manufacturing
Current industrial practice
Acknowledgments
References
Composite injection overmoulding
Injection moulding process
Composite injection overmoulding-Background
Composite injection overmoulding process
Single-stage injection overmoulding
Two-stage composite injection overmoulding
Material characteristics
Material compatibility
Interface formation in injection overmoulding
Heat transfer and interface temperature
Healing at the interface
Common issues in composite injection overmoulding
Weak bonding between the overmould and the composite insert
Material-related issues
Processing-related issues
Warpage and residual stresses
Fibre distortion
Summary
References
Design for manufacture
Introduction
Design for manufacturability
Manufacturing-informed performance
Typical phenomena in composites manufacturing
Continuous fibre composites
Automated tape laying
Polymer melting and kinetics
Simulation methods
Manufacturability
Manufacturing-informed performance
Laminate stamping
Draping and forming
Simulation methods
Design for manufacturability
Manufacturing-informed performance
Liquid composite moulding
Darcy flow through porous media
Simulation methods
Manufacturability
Manufacturing-informed performance
Discontinuous fibre composites
Compression moulding
Flow of fibre-filled suspensions
Simulation methods
Manufacturability
Manufacturing-informed performance
Future trends
References
Process simulation: Fabric forming
Introduction
Simulation frameworks
Kinematic models vs finite element methods
Implicit vs explicit algorithms
FE modelling scale
Fabric material modelling
Continuous approach
Hypoelastic continuous model
Hyperelastic continuous model
Discrete or mesoscale approach
Semi-discrete approach
Simulation for process design
Defect prediction and visualisation
Membrane-element-based simulation
Shell-element-based simulation
Process optimisation
In-plane constraint optimisation
Spring-loaded clamps
Blank holder force
Selective intra-ply stitch removal
Simulation for large-scale preforms
Multi-ply forming simulation
Summary
References
Process simulation: Moulding processes
Introduction
Short-fibre reinforced polymers
Discrete numerical simulation of the fibre orientation
Fibre motion equations: Translation
Fibre motion equations: Rotation
Process modelling and simulation
Flow model
Case study
Increasing fibre length: From SMC to RTM
Micromechanical model
Flow regimes
Lubrication approximation
Squeeze flow in narrow gaps
Case studies
Prepreg compression moulding
3D stokes flow problem in thin gaps
Ericksen fluid flow model in a laminate
Case study
Summary
References
Digital factory
Introduction to digital factories and digital twins
Digital twin
Digital factory
State of the art
Simulation of factories
Simulation of manufacturing
Simulation of parts
Simulation of robot cells
Instrumentation and measurement
Sensor systems in manufacturing
Interfaces for manufacturing equipment and sensors
Communication between interfaces
Data management
Current application in structural composites
Summary
References
Cost, rate, and robustness
Introduction
Different approaches to cost modelling
Cost estimation and `should-cost
Technical cost modelling
Key considerations
Types of cost models
Cost model calculation
Process flow
Cycle time and utilisation
Shifts and parallel activities
Depreciation and amortisation
Scrap and reject
Other key concepts
Cost analysis and examples
Example production scenarios
Cost analysis
Sensitivity analysis
Investment planning and business economics
Business case analysis
RandD investment and budgeting
Supply chain planning
Summary
References
Materials waste reduction
Introduction
Composite consumption and waste generation-By sector
Sources of composite waste
Storage 1%
Lay-up: 0%-50%
Cut-out waste
Trimming waste
Lay-up defects
Curing mistakes: 1%
Finishing: 2%-40%
Impact of process selection on material yield
Case study: Impact of process selection
Strategies for improving material yield
Digital manufacturing
Real-time defect detection techniques
Zone-based design
Nesting optimisation
Case study - Nesting optimisation
Summary
Acknowledgements
References
Disassembly
Introduction
Drivers for disassembly
Circular economy strategies and standards
Directives, legislation, and alternative approaches
Automotive
Aerospace
Marine and renewable (wind) energy
Summary
Design for disassembly
Holistic DfD approach
DfD tools
Industry 4.0
Component traceability
Summary
Disassembly technologies
Disassembly-embedded design
Active disassembly
Shape memory effects
Smart adhesives
Tailored adhesive formulations
Active substrates and tapes
Chemical additives
Physical additives
Summary
Concluding remarks
References
Fibre recovery and re-use
Introduction
Motivation
Types of waste
Waste pre-treatment options
End use opportunities
Requirements for end use applications
Cost and added value
The importance of fibre packing
Recovery processes
Mechanical fibre recovery
Thermal processes for fibre recovery
Combustion with energy recovery
Thermal decomposition of thermoset composite materials
Pyrolysis
Fluidised bed
Microwave pyrolysis
Solvolysis processes for fibre recovery
High-temperature and high-pressure solvolysis processes
Low-temperature and low-pressure solvolysis processes
Properties of recovered fibres
Mechanical properties of glass fibre
Mechanical properties of carbon fibre
Surface properties
Physical properties
Conversion processes
Direct re-use - Shredded laminate
Direct re-use - Uncured prepreg
Dry fibre - Trim scrap and bobbin ends
End-of-life components
Input formats and challenges
Conversion options
Re-use of thermoplastic composites
Achievable mechanical properties
Discussion and future prospects
Environmental considerations
References
Index
