Study on degradation of glass fiber sheet moulding compound under hot water

摘要

followed by tensile test with Acoustic Emission (AE) monitoring and microscopic investigation to evaluate its initial fracture and degradation mechanism.The specimens were prepared in two perpendicular directions determined as Y (resin flowing direction) and X direction in the paper.
　　The initial fracture generated in tensile test was determined by both tensile stress-strain curve and AE measurement (140 kHz and 1 MHz resonant frequencies).The result shows that different fiber orientation and mechanical property between Y and X are occurred due to the fiber flowing during molding.In most cases Y specimen tensile strength and modulus is higher than X specimen.Initial fracture stress from stress-strain curve and AE measurement were obtained and was proposed as an allowable products design.

目录

声明

Preface

TABLE OF CONTENTS

1 Introduction

1．1 Background

1．2 Aim and objectives

1．3 Structure of the work

1．4 Thesis outline

2 Literature review

2．1 SMC manufacturing process

2．2 Current research on SMC

2．2．1 Mechanical properties of glass fiber SMC under hot water

2．2．2 Hygrothermal aging of SMC

2．3 Degradation behavior of glass fiber reinforced plastic(GFRP)

2．3．1 Bending and AE of fiber reinforced plastic(FRP)

2．3．2 Effect of tap water and sea water immersed GFRP bars under lab and typical field conditions

2．3．3 Residual strength of hydrothermally aged GFRP by AE

2．3．4 Weight-change measurement of FRP under hot water

2．3．5 Water absorption and blistering investigation under hot water

3 Experimental

3．1 Material and equipments

3．1．1 Materials

3．1．2 Hot water immersion

3．1．3 Equipments used

3．2 Principle of acoustic emission

3．3 Tensile and AE measurement technique

3．4 Fiber surface morphology by SEM

4 Results and discussion

4．1 Fracture morphology

4．2 Interface characterization

4．3 Initiate fracture determination during tensile test

4．4 Knee point stress and AE generated stress during tensile test

4．5 Mechanical Properties

4．5．1 Tensile modulus and tensile strength

4．5．2 Materials design-safety factor

4．5．3 Materials design-Anisotropy

Conclusion

List of Abbreviations

References

Appendix