Bending Behavior of Thermoplastic Composite Sheets (eBook)

Viscoelasticity and Temperature Dependency in the Draping Process

Steffen Ropers (Autor)

eBook Download: PDF

2017 | 1st ed. 2017
XXIII, 93 Seiten
Springer Fachmedien Wiesbaden (Verlag)
978-3-658-17594-8 (ISBN)

Infos

Within the scope of this work, Steffen Ropers evaluates the viscoelastic and temperature-dependent nature of the bending behavior of thermoplastic composite sheets in order to further enhance the predictability of the draping simulation. This simulation is a useful tool for the development of robust large scale processes for continuously fiber-reinforced polymers (CFRP). The bending behavior thereby largely influences the size and position of wrinkles, which are one of the most common processing defects for continuously fiber-reinforced parts. Thus, a better understanding of the bending behavior of thermoplastic composite sheets as well as an appropriate testing method along with corresponding material models contribute to a wide-spread application of CFRPs in large scale production.

Steffen Ropers studied mechanical engineering at the University of Erlangen-Nuremberg, Germany, and the University of Wisconsin-Madison, U.S., with majors in polymer engineering and manufacturing technology. He is currently employed at the materials and processes department of a notable automotive OEM.

 

Inhalt

Foreword 6
Danksagung 8
Contents 10
List of Figures 12
List of Tables 16
Nomenclature 17
Kurzfassung 20
Abstract 21
1 Introduction 22
1.1 Motivation and Objective 23
1.2 Outline 25
2 Thermoplastic Prepregs 26
2.1 Thermoplastic Polymers 26
2.2 Viscoelasticity of Polymers 27
2.2.1 Boltzmann Superposition Principle 29
2.2.2 Maxwell Model 31
2.3 Structure of Continuous Fiber Reinforced Polymers 34
2.4 Manufacturing of Thermoplastic Prepregs 36
2.5 Processing: Thermoforming Process 39
3 Draping Simulation of Thermoplastic Prepregs 42
3.1 Overview of Draping Simulation Techniques 42
3.1.1 Kinematic Approach 42
3.1.2 Finite Element Approach 42
3.2 Material Characterization of Thermoplastic Prepregs 44
3.2.1 Tensile Characterization 45
3.2.2 Shear Characterization 45
Picture Frame Test 46
Bias Extension Test 48
3.2.3 Friction Characterization 49
4 Bending Characterization of Textile Composites 51
4.1 Materials 51
4.2 Cantilever Test 53
4.2.1 Cantilever Experiments on GF/PA6 Fabric 56
4.3 Dynamic Mechanical Analysis 60
4.3.1 DMA Experimental Set-Up 61
4.3.2 DMA Results GF/PA6 Fabric 63
4.3.3 DMA Results GF/PA6 Fabric, conditioned 63
4.3.4 DMA Results CF/PA6 UD Tape 65
4.4 Dynamic, High Curvature Bending Tests 65
4.4.1 Test Procedure for GF/PA6 and CF/PA6 67
4.4.2 Results of Bending Experiments CF/PA6 UD Tape 68
4.4.3 Results of Bending Experiments GF/PA6 Fabric 71
4.5 Oscillatory Constant Deformation Rate 74
4.6 Sinusoidal Deformation 78
5 Simulation of Bending Behavior 80
5.1 Cantilever Results as Input for Draping Simulation 80
5.2 Temperature Proportionality Method 82
5.3 Linear Viscoelastic Model 85
5.3.1 Material Model subjected to Single Deformation in Rheometer Bending Experiments 89
5.3.2 Material Model subjected to Oscillatory Constant Deformation Rate 91
5.4 Non-Linear Viscoelastic Model 93
5.4.1 Material Model subjected to Single Deformation and Relaxation 96
5.4.2 Temperature Dependency 97
5.4.3 Material Model subjected to Oscillatory Constant Deformation Rate 99
5.4.4 Material Model subjected to Sinusoidal Deformation 100
6 Conclusion 102
6.1 Bending Characterization 102
6.2 Simulation of Bending Behavior 104
Bibliography 106

Produkt-Details

• Erscheint lt. Verlag: 7.3.2017
• Reihe/Serie: AutoUni – Schriftenreihe
• Reihe/Serie: AutoUni – Schriftenreihe
• Zusatzinfo: XXIII, 93 p. 81 illus., 21 illus. in color.
• Verlagsort: Wiesbaden
• Sprache: englisch
• Themenwelt: Technik ► Bauwesen
• Themenwelt: Technik ► Maschinenbau
• Themenwelt: Wirtschaft
• Schlagworte: Finite Element Analysis (FEA) • forming • Mechanical Testing • Textile Composites • Thermo-mechanical • thermoplastic resin
• ISBN-10: 3-658-17594-X / 365817594X
• ISBN-13: 978-3-658-17594-8 / 9783658175948