Interface Fracture and Delaminations in Composite Materials (eBook)

Preface 7
Contents 8
Symbols 10
1 Introduction 14
References 19
Part I Interface Fracture 20
2 Fundamentals of Interface Fracture Mechanics 21
2.1 Stress and Displacement Field in the Neighborhood of an Interface Crack Tip 22
2.2 Interface Energy Release Rate 24
2.3 Fracture Criterion 25
References 28
3 Calculation of Stress Intensity Factors -- An Interface Crack 30
3.1 Finite Element Method 30
3.2 Displacement Extrapolation Method 33
3.3 M-Integral 35
3.3.1 Two Dimensions 35
3.3.2 Three Dimensions 39
3.4 Virtual Crack Closure Technique 42
References 46
4 Testing--Interface Crack Between Two Isotropic Materials 49
References 53
Part II Delaminations in Composites 55
5 Mathematical Treatment of Delaminations 56
5.1 The 0°//90° Interface 58
5.2 The +45°//-45° Interface 61
5.3 The +30°//-60° and -30°//+60° Interfaces 65
5.4 An Interface Between Two Woven Plies 70
5.5 Afterward 71
References 74
6 Methods of Calculating Stress Intensity Factors--Delaminations 76
6.1 Displacement Extrapolation 76
6.2 M-Integral 79
6.3 Virtual Crack Closure Technique 82
References 84
7 Testing--Delamination Between Two Dissimilar Plies 85
7.1 Failure of a Delamination in a Cross-Ply 85
7.2 Beam Type Specimens 90
References 96
Appendix A Stress and Displacement Functions for the First Term of the Asymptotic Expansion of an Interface Crack Between Two Linear Elastic, Homogeneous and Isotropic Materials 98
Appendix B Matrices Ak, Bk and Bk-1 for Different Anisotropic Material Pairs 100
B.1 The 0°/90° Pair 102
B.2 The +45°/-45° Pair 106
B.3 The +30°/-60° Pair and the -30°/+60° Pair 112
B.4 Multi-directional Woven Material 115
Appendix C Stress and Displacement Functions for the First Term of the Asymptotic Expansion of an Interface Crack Between Two Anisotropic Materials 117
Index 124