Resin Transfer Moulding for Aerospace Structures

539 Pages·1998·19.08 MB·English

by  Bernd Räckers (auth.)

Resin Transfer Moulding for
Aerospace Structures
Resin Transfer Moulding
for Aerospace
Structures
Edited Ьу
Teresa Kruckenberg
М.
Cooperative Research Centre for Advanced Composite Structures
Bankstown, New South Wales,
Australia
and
Rowan Paton
Cooperative Research Centre for Advanced Composite Structures
Fishermans Bend, Victoria,
Australia
...
~
"
SPRINGER SCIENCE+BUSINESS MEbIA, В.У.
Library of Congress Cataloging-in-Publication Data is available.
ISBN 978-94-010-5906-0 ISBN 978-94-011-4437-7 (eВook)
DOI 10.1007/978-94-011-4437-7
Printed оп acid-free paper
АН rights reserved
© 1998 Springer Science+Business Media Dordrecht
Originally published Ьу Кluwer Academic Publishers in 1998
Softcover reprint of the hardcover 1s t edition 1998
No part of the material protected Ьу this copyright notice тау Ье reproduced or
utilized in any form or Ьу any means, electronic or mechanical, including
photocopying, recording or Ьу any information storage and retrieval system, without
prior permission from the copyright owners.
Contents
List of contributors xv
h~ ~
Acknowledgements xxi
Chapter 1 Introduction to resin transfer moulding 1
Bernd Rackers
1.1 Introduction 1
1.1.1 Is resin transfer moulding a new process? 2
1.1.2 Reasons for resin transfer moulding 3
1.1.3 Basic principles and requirements
for resin transfer moulding 5
1.1.4 Outline of resin transfer moulding development work 12
1.1.5 Resin transfer moulding and resin film infusion:
common and different aspects 14
1.2 Current and future applications for resin transfer moulding
and resin film infusion 15
1.2.1 Examples for applications and development 16
1.2.2 Outlook for resin transfer moulding in aerospace
applications 22
References 24
Chapter 2 Injection equipment 25
Mitch Petervary
2.1 Introduction 25
2.2 Selection considerations 26
2.2.1 Selection of a manufacturer 26
2.2.2 Application-specific considerations 26
2.3 Basic principles of resin delivery for resin transfer moulding 28
2.3.1 Basic elements 28
2.3.2 Additional features and variations 32
vi Contents
2.3.3 Constant pressure versus constant flow rate 36
2.4 Conclusions 39
References 40
List of manufacturers 41
Chapter 3 Materials 42
Mac Puckett and Mitch Petervary
3.1 Introduction 42
3.1.1 Background: thermoplastic and thermoset materials 43
3.1.2 Engineering the resin transfer moulding process:
the interaction of chemistry and physics
in a reactive process 47
3.1.3 Tough composites: tough resins
and composite architecture 53
3.1.4 Epoxy systems 55
3.1.5 Phenolic thermoset materials 61
3.1.6 Cyanate resins 62
3.1.7 Bismaleimides 64
3.2 Fibre reinforcements 65
3.2.1 Materials for fibre reinforcements 67
3.2.2 Bundling fibres: tows, yarns and woven fabrics 74
3.2.3 Finishes, sizings and coatings 74
3.3 Conclusions 76
References 78
List of manufacturers 81
Chapter 4 Advanced reinforcements 83
Michael Bannister and Israel Herszberg
4.1 Introduction 83
4.2 Stitching 84
4.3 Weaving 91
4.4 Braiding 96
4.5 Knitting 102
4.6 Non-crimp fabric 105
4.7 Conclusions 108
References 109
Chapter 5 Fabric drape modelling and preform design 112
Andrew C. Long and Chris D. Rudd
5.1 Introduction 112
5.2 Fundamentals of fabric deformation 114
5.2.1 Deformation mechanisms 114
5.2.2 Experimental characterisation 116
5.3 Kinematic drape modelling 121
Contents vii
5.3.1 Assumptions 121
5.3.2 Fundamental equations 121
5.3.3 Draping algorithm 124
5.3.4 Examples 124
5.4 Drape model validation 130
5.4.1 Fibre volume fraction variation 130
5.4.2 Automated strain analysis 131
5.5 Effects on processing and performance characteristics 135
5.5.1 Impregnation properties 136
5.5.2 Mechanical properties 141
5.6 Discussion 144
References 146
Chapter 6 Overview of fibre preforming 148
Vivek Rohatgi, L. James Lee and Adrian Melton
6.1 Fibre preforming - why is it needed? 148
6.2 Use of binders and tackifiers for fibre preforming 151
6.3 Fibre preforming techniques 152
6.3.1 Simultaneous preforming processes 152
6.3.2 Sequential preforming processes 153
6.4 Net-shape preforming of woven fibre mats by means
of tackifiers 161
6.5 Design of preform tools 170
6.6 Design of preforming equipment 171
6.7 Preform storage 172
6.8 Conclusions 173
References 174
Chapter 7 Preform permeability 177
Richard Parnas
7.1 Introduction 177
7.1.1 Flow through porous media 177
7.1.2 The importance of permeability in liquid
composite moulding 179
7.2 Experimental methods 181
7.2.1 Unidirectional flow method 181
7.2.2 Radial flow method 198
7.3 The general three-dimensional case 206
7.3.1 Analysis of unidirectional flow data 207
7.3.2 Numerical tests 213
7.3.3 Three-dimensional flow experiments 218
7.4 Summary 219
References 222
viii Contents
Chapter 8 Modelling and simulation of flow, heat transfer
and cure 225
Suresh G. Advani and Pavel Simacek
8.1 Introduction 225
8.1.1 The resin transfer mould filling process 225
8.1.2 The need for a process model of resin impregnation 225
8.1.3 Microscopic and macroscopic flow 228
8.2 Flow and preform architecture 228
8.2.1 Flow in random fabrics 230
8.2.2 Flow in woven or stitched fabrics 231
8.2.3 Unsaturated flow 233
8.2.4 Transverse flow in multilayer preforms 233
8.3 Deformation of fabrics and its impact on flow 234
8.3.1 In-plane deformation 235
8.3.2 Transverse compaction 236
8.3.3 Racetracking 237
8.4 Analytical and numerical models for the preforming stage 238
8.4.1 Preform deformation 238
8.4.2 Permeability 242
8.5 Governing equations 245
8.5.1 Isothermal flow modelling 245
8.5.2 The two-dimensional problem 246
8.5.3 Formulation using a fill factor 247
8.5.4 The energy equation 248
8.5.5 Boundary conditions for energy transfer 249
8.5.6 Cure kinetics coupling 250
8.5.7 Temperature-dependent viscosity 251
8.5.8 The heat dispersion effect 252
8.5.9 Non-Newtonian fluids 253
8.6 Numerical formulations and simulations 253
8.6.1 Complexity of geometry 254
8.6.2 The finite element/control volume approach
in two dimensions 254
8.6.3 Coupling with heat transfer
and cure - the two-dimensional model 259
8.6.4 The pure finite element approach to mould filling 260
8.6.5 Other numerical approaches 260
8.7 Critical issues 261
8.7.1 Levels of sophistication to build these models 263
8.7.2 Inputs 264
8.8 Case study 267
8.8.1 The permeability model 268
8.8.2 Draping of the mould 269
8.8.3 Filling simulation 272
Contents ix
8.8.4 Conclusions 274
8.9 The use of simulations as a design tool 275
References 277
Chapter 9 Tooling fundamentals for resin transfer moulding 282
Mark Wadsworth
9.1 Introduction to resin transfer moulding tooling 282
9.2 Resin transfer moulding tooling materials and processes 284
9.2.1 Selecting mould materials 284
9.2.2 The effects of tolerances on tooling process selection 286
9.2.3 Methods of creating the mould shape 287
9.2.4 Fabricated tooling 288
9.2.5 Replicated tooling 290
9.3 Tooling cost considerations 299
9.3.1 Manufacturing rate and volume capacity 299
9.3.2 Prototype moulds 299
9.3.3 Rigid versus semi-rigid tooling 300
9.3.4 The effect of precision on tooling costs 300
9.3.5 Estimating the durability of moulds 300
9.4 Geometric considerations for moulds for use
in resin transfer moulding 302
9.4.1 Net versus excess moulding 302
9.4.2 Mould gap design 303
9.4.3 Parting line considerations 303
9.4.4 Designing the tool flange geometry 304
9.4.5 Accomodating undercuts and zero draft situations 308
9.4.6 Guidance of tool inserts 309
9.4.7 Designing preform control and debulk features 309
9.4.8 Free-floating inserts 311
9.4.9 Part demoulding considerations 312
9.5 Thermal considerations in mould design
in resin transfer moulding 314
9.5.1 Mould heating 314
9.5.2 Thermal expansion of the mould 317
9.6 Physical requirements of tooling in resin transfer moulding 318
9.6.1 Surface characteristics 318
9.6.2 Pressure forces on the mould 320
9.6.3 Selecting a mould clamping system 323
9.7 Process considerations for resin transfer moulding tooling 326
9.7.1 Resin injection port 326
9.7.2 Locating injection ports and vents 327
9.7.3 Plumbing requirements for sequential injection 328
9.7.4 Designing resin distribution manifolds 329
9.7.5 Air vent features 330
x Contents
9.7.6 Designing preform tooling 330
9.8 Examples of resin transfer moulding tooling 331
9.8.1 Example 1 332
9.8.2 Example 2 332
9.8.3 Example 3 333
9.8.4 Example 4 335
Reference 337
Further reading 337
Chapter 10 Tooling inserts for resin transfer moulding 338
Mark Thiede-Smet and Mark Wadsworth
10.1 Introduction 338
10.2 Foam cores 339
10.2.1 Foam selection 341
10.2.2 Method for foaming core shapes 346
10.2.3 Methods for machining core shapes 349
10.2.4 Processing considerations when using foam cores 349
10.2.5 Lessons learned from using foam cores 351
10.3 Honeycomb and other open-cell cores 352
10.3.1 Methods of preventing resin from filling the
honeycomb cells 353
10.3.2 Honeycomb selection for resin transfer moulding 356
10.3.3 Special considerations 357
10.4 Balsa wood cures 359
10.4.1 Balsa selection 359
10.4.2 Processing considerations 360
10.5 Bladders 360
10.5.1 Types of bladders 361
10.5.2 Processing considerations when using bladders 365
10.5.3 Bladder material selection 367
10.5.4 Making internal bladders 367
10.6 Phase change tooling inserts 370
10.6.1 Selecting melt-out and soluble mandrel materials 370
10.6.2 Eutectic salts 371
10.6.3 Melt-out metal alloys 373
10.6.4 Waxes 373
10.6.5 Soluble plasters and conglomerates 374
10.6.6 Break-out mandrels 374
10.6.7 Creating the mandrel shape 375
10.6.8 Sealing the mandrel surface 377
10.6.9 Processing considerations for melt-out mandrels 378
10.6.10 Thermal considerations for melt-out mandrels 379
10.7 Extractable tooling inserts 380
10.7.1 Material selection 380
Contents xi
10.7.2 Design and processing considerations 382
References 386
Chapter 11 Manufacturing and tooling cost factors 388
Teresa Kruckenberg
11.1 Introduction 388
11.2 Recurring cost factors 389
11.2.1 Effect of manufacturing quantity 389
11.2.2 Material cost factors 390
11.2.3 Manufacturing cost factors 392
11.3 Non-recurring cost factors 400
11.3.1 Injection equipment 400
11.3.2 Heat source 402
11.3.3 Mould costs 403
11.3.4 Certification cost factors 405
11.4 Applications 406
11.5 Case studies 406
11.5.1 Concept 1: flat panel 407
11.5.2 Concept 2: curved panel 408
11.5.3 Concept 3: stiffened panel 408
11.5.4 Concept 4: flap 408
11.5.5 Summary 408
References 411
Chapter 12 Data acquisition: monitoring resin position,
reaction advancement and processing properties 412
David E. Kranbuehl and Al Loos
12.1 Introduction 412
12.2 Instrumentation 415
12.3 Theory 415
12.4 Calibration: monitoring cure in multiple time-temperature
processing cycles 417
12.5 Monitoring resin infiltration in conventional resin transfer
moulding, and model verification 420
12.6 In situ real time flow sensing in resin film infusion
and process monitoring 425
12.7 Smart automated control 428
12.8 Conclusions 429
Acknowledgements 430
References 431
List of manufacturers 433