On the Time and Temperature Dependent Behaviour of Laminated Amorphous Polymers Subjected to Low-Velocity Impact (eBook)

​Dr.-Ing. Andreas Rühl studied Mechanical Engineering at the Technische Hochschule Mittelhessen in Gießen. Since 2011 he is employed at the Institute of Mechanics and Materials as a research associate in the working group of Prof. Dr.-Ing. habil. Stefan Kolling. During this time he completed his doctorate (Dr.-Ing.) in a cooperative graduation with the Technical University Darmstadt in the working group of Prof. Dr.-Ing. Jens Schneider. His research interests are in the area of thermomechanical characterization and modelling of polymeric materials. 

Danksagung 6
Abstract 7
Zusammenfassung 8
Contents 9
Glossaries 12
1 Introduction 15
1.1 Motivation 15
1.2 State of the Art 16
1.3 Aim and Structure of the Present Work 21
2 Fundamentals 23
2.1 Continuum Mechanics 23
2.1.1 Kinematics 23
2.1.2 Stress 28
2.2 Polymer Materials Theory 30
2.2.1 Linear Elasticity 30
2.2.2 Hyperelasticity 31
2.2.3 Viscoelasticity 34
2.2.4 Time-Temperature Superposition 40
2.2.5 Numerical Treatment of Viscoelasticity 43
2.2.6 Thermoviscoelasticity 44
2.2.7 Adiabatic Heating 45
2.3 Materials and Laminated Setup 46
2.3.1 Poly(methyl Methacrylate) (PMMA) 46
2.3.2 Thermoplastic Polyurethane (TPU) 52
2.3.3 PMMA-TPU Laminate 55
3 Experimental Investigation 58
3.1 General Experimental Procedures 59
3.1.1 Specimen Preparation 59
3.1.2 Digital Image Correlation 60
3.1.3 Infrared Surface Temperature Measurements 61
3.1.4 Sensors and Signal Processing 62
3.2 Experimental Investigation of PMMA 63
3.2.1 Transient Plane Source Method Experiments 63
3.2.2 Dynamic Mechanical Thermal Analysis 65
3.2.3 Uniaxial Tensile Tests 71
3.2.4 Three-Point Bending Tests 75
3.2.5 Dart Impact Tests 77
3.3 Experimental Investigation of TPU Interlayers 82
3.3.1 Transient Plane Source Method Experiments 82
3.3.2 Dynamic Mechanical Thermal Analysis 83
3.3.3 Uniaxial Tensile Tests 85
3.3.4 Biaxial Tensile Tests 91
3.4 Experimental Investigation of PMMA-TPU Laminates 94
3.4.1 Three-Point Bending Test 94
3.4.2 Clamped Bending Tests 98
3.4.3 Dart Impact Tests 100
3.5 Summary 104
4 Material Modelling of PMMA 106
4.1 Linear Viscoelasticity 107
4.2 Hyper-Viscoelasticity 111
4.3 Thermo-Hyperviscoelasticity 114
4.4 Linear Thermoviscoelasticity Using the Arrhenius Shift Equation 115
4.5 A Simplified Failure Criterion 118
4.6 Summary 121
5 Material Modelling of TPU 122
5.1 Hyperelasticity 122
5.2 Tabulated Hyperelasticity 123
5.3 Hyper-Viscoelasticity 124
5.4 Thermo-Hyperviscoelasticity 126
5.5 Adiabatic Heating 126
5.6 Summary 128
6 Simulation of PMMA-TPU Laminate 129
6.1 FE-Modelling 129
6.1.1 Mesh Structure and Element Types 130
6.1.2 Coincident Element Modelling 130
6.1.3 Tied and Tiebreak Contacts for Delamination Modelling 132
6.2 Mechanical Behaviour 133
6.2.1 Dart Test 133
6.2.2 Global Energy Failure Threshold 134
6.2.3 Clamped Bending Simulations 136
6.3 Temperature Dependent Mechanical Behaviour 137
6.4 Coupled Thermomechanical Behaviour 139
6.5 Summary 141
7 Component Tests and Validation 142
7.1 Experimental Setup 142
7.2 PU Adhesive 144
7.3 Monolithic Materials 145
7.4 PMMA-TPU Laminate 147
7.5 Validation of the Finite Element Model 148
7.6 Summary 152
8 Summary and Outlook 153
References and Regulations 155
References 155
Standards 164
Manuals and Data Sheets 165
Appendix AExperiments 166
A.1 Materials used in Experiments 166
A.2 Transient Plane Source Method 166
A.3 Dynamic Mechanical Thermal Analysis 168
A.4 Uniaxial Tensile Tests 169
A.5 Three-Point Bending Test 171
A.6 Dart Impact Tests 173
Appendix BMaterial Modelling 174
B.1 Material Parameters for PMMA 174
B.2 Material Parameters for TPU 175