Page 13 - Engineered Interfaces in Fiber Reinforced Composites

X Contents
3.2.1. Introduction 44
3.2.2. Single Fiber Compression Test 44
3.2.3. Fiber Fragmentation Test 45
3.2.4. Fiber Pull-out Test 5 1
3.2.5. Microindentation (or Fiber Push-out) Test 56
3.2.6. Slice Compression Test 58
3.2.7. Comparison of Microcomposite Tests and Experimental Data 59
3.3. Interlaminar/Intralaminar Properties 61
3.3.1. Introduction 61
3.3.2. Short Beam Shear Test 62
3.3.3. Iosipescu Shear Test 66
3.3.4. [ f 45"Is Tensile Test 69
3.3.5. [ lo"] Off-axis Tensile Test 70
3.3.6. Rail Shear Test 71
3.3.7. In-plane Lap-shear Test 72
3.3.8. Transverse Tensile Test 72
3.4. Interlaminar Fracture Toughness 74
3.4.1. Delamination 74
3.4.2. Mode 1 Interlaminar Fracture Tests (IFT) 76
3.4.3. Mode I1 Interlaminar Fracture Tests 81
3.4.4. Mode I Edge Delamination Tests 83
References 85

Chapter 4. Micromechanics of Stress Transfer Across the Interface 93

4.1. Introduction 93
4.2. Fiber Fragmentation Test 94
4.2.1. Introduction 94
4.2.2. Early Shear-Lag Models 97
4.2.3. An Improved Model based on a Fracture Mechanics Approach 101
4.2.4. An Improved Model based on a Shear Strength Criterion 110
4.3. Fiber Pull-Out Test 125
4.3.1. Introduction 125
4.3.2. Solutions for Stress Distributions 128
4.3.3. Interface Debond Criterion and Partial Debond Stress 131
4.3.4. Instability of Debond Process 135
4.3.5. Characterization of Interface Properties 138
4.3.6. Multiple Fiber Composite Model 139
4.3 7. Two-way Debonding Phenomenon 147
4.4. Fiber Push-out 150
4.4.1. Solutions for Stress Distributions 150
4.4.2. Debond Criterion and Debond Stresses 152
4.4.3. Comparisons between Fiber Pull-out and Fiber Push-out 154
4.5. Cyclic Loading in Fiber Pull-out and Fiber Push-out 156
4.5.1. Introduction 156