Residual Stresses in Composite Materials (eBook)

Cover 
1 
Residual stresses in composite materials 4
Copyright 
5 
Contents 6
Contributor contact details 12
Woodhead Publishing Series in Composites Science and Engineering 16
Introduction 20
Part I Measurement and modelling 
22 
1 The importance of measuring residual stresses in composite materials 
24 
1.1 Introduction 24
1.2 Categories of residual stresses 25
1.3 Effects of residual stresses 28
1.4 The importance of residual stress measurement 31
1.5 Issues in the measurement of residual stresses 32
1.6 Techniques for measuring residual stress in composites 32
1.7 References 34
2 Destructive techniques in the measurement of residual stresses in composite materials: an overview 
36 
2.1 Introduction 36
2.2 The layer removal method 37
2.3 The Sachs (boring) method 38
2.4 Hole-drilling methods 
39 
2.5 The ring-core method 
46 
2.6 The cutting method 48
2.7 The contour method 48
2.8 The ply sectioning method 50
2.9 The radial cutting method 51
2.10 Matrix removal methods 52
2.11 Micro-indentation methods 
54 
2.12 The slitting method 56
2.13 The first ply failure method 
61 
2.14 The measurement of curvature method 63
2.15 Heating methods 66
2.16 Conclusions 66
2.17 References 67
3 Non-destructive testing (NDT) techniques in the measurement of residual stresses in composite materials: an overview 
79 
3.1 Introduction 79
3.2 The X-ray diffraction method 79
3.3 The neutron diffraction method 82
3.4 The Raman spectroscopy method 83
3.5 The photoelasticity method 85
3.6 Other optical methods 86
3.7 The acoustic wave method 87
3.8 Methods based on interferometry 87
3.9 The cure referencing method 88
3.10 Measurement methods using sensors 89
3.11 The electrical resistance method 91
3.12 Conclusions 91
3.13 References 92
4 Measuring residual stresses in composite materials using the simulated hole-drilling method 
97 
4.1 Introduction 97
4.2 The hole-drilling method in isotropic materials 
101 
4.3 The hole-drilling method in orthotropic materials 
109 
4.4 The hole-drilling method in laminated composites 
115 
4.5 Key issues in using the hole-drilling method 
120 
4.6 Conclusions 138
4.7 References 139
5 Measuring residual stresses in composite materials using the slitting/crack compliance method 
142 
5.1 Introduction 142
5.2 The development of the slitting method 143
5.3 Theoretical basis 143
5.4 The fi nite element method (FEM) for calculation of compliance functions 150
5.5 Residual shear stresses: effects on measured strains 156
5.6 Case study: residual stress measurement in a carbon/epoxy laminate 164
5.7 Conclusions and future trends 170
5.8 References 171
6 Measuring residual stresses in homogeneous and composite glass materials using photoelastic techniques 
173 
6.1 Introduction 173
6.2 Measuring residual stresses in axisymmetric glass articles 174
6.3 Measuring residual stresses in glass articles of arbitrary shape 181
6.4 Measuring residual stresses in automotive and building glass 186
6.5 Conclusions 192
6.6 Acknowledgement 192
6.7 References 192
7 Modeling residual stresses in composite materials 
194 
7.1 Introduction 194
7.2 Selecting an appropriate model 196
7.3 The elastic behavior models 199
7.4 The viscoelastic behavior models 201
7.5 Modified classical lamination theory (CLT) for modeling residual stresses 
206 
7.6 Future trends 210
7.7 References 211
Part II Residual stresses in different types of composites 
216 
8 Understanding residual stresses in polymer matrix composites 
218 
8.1 Introduction 218
8.2 Formation of residual stresses 220
8.3 Effects of residual stresses 226
8.4 Methods of measurement: destructive methods 232
8.5 Methods of measurement: non-destructive methods 
236 
8.6 Methods of prediction 241
8.7 Conclusion 244
8.8 References 247
9 Understanding residual stresses in metal matrix composites 
254 
9.1 Introduction 254
9.2 Factors affecting the magnitude and distribution of residual stresses in composites 256
9.3 The effects of residual stress on the failure of metal matrix composites (MMCs) 266
9.4 The effects of residual stress on the elevated temperature behaviour of MMCs 270
9.5 Future trends 273
9.6 References 273
10 Understanding residual stresses and fracture toughness in ceramic nanocomposites 
277 
10.1 Introduction 277
10.2 Overview of ceramic nanocomposites 277
10.3 Residual stress inside ceramic nanocomposites 288
10.4 Toughening and strengthening mechanisms in ceramic nanocomposites 292
10.5 Surface residual stress 302
10.6 Future trends 307
10.7 References 308
11 Measuring and modelling residual stresses in polymer-based dental composites 
314 
11.1 Introduction 314
11.2 Experimental and modelling approaches to study residual stresses in dental composites 315
11.3 Case study: the development of local stresses in four different dental composites 322
11.4 Further applications of the modelling approach 328
11.5 References 330
12 Understanding residual stresses in thick polymer composite laminates 
332 
12.1 Introduction 332
12.2 Modelling the curing process in thick laminated composites 335
12.3 Understanding the curing process 340
12.4 Residual stresses in thick laminated composites 344
12.5 Methods of measurement of residual stresses in laminated composites 353
12.6 Future trends 367
12.7 Acknowledgments 368
12.8 References 368
13 Reduction of residual stresses in polymer composites using nano-additives 
371 
13.1 Introduction 371
13.2 Application of nano-additives to enhance the thermal and mechanical properties of polymer composites 
373 
13.3 Case study: reduction of residual stresses in carbon/epoxy laminates using carbon nanofi bres (CNFs) 378
13.4 Conclusions and future trends 390
13.5 References 392
Index 396