Investigation on Mechanical Properties and Fracture Behavior by Nanoscale Graphene Discontinuous Carbon Fiber Reinforced Copolymer (Epoxy/Benzoxazine) Composite
碩士 === 國立清華大學 === 動力機械工程學系 === 103 === This study is focuses on the characteristics of the benzoxazine/epoxy copolymer matrix, combined thegraphene and micro-scale short carbon fibers to be reinforcement. In order to investigate the reinforced mechanism of the nano-scale and micro-scale additive, t...
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ndltd-TW-103NTHU53110232019-05-15T22:18:04Z http://ndltd.ncl.edu.tw/handle/k9985k Investigation on Mechanical Properties and Fracture Behavior by Nanoscale Graphene Discontinuous Carbon Fiber Reinforced Copolymer (Epoxy/Benzoxazine) Composite 石墨烯補強共聚物高分子不連續碳纖維複合材料之機械性質與破壞行為研究 Juang, Jia-Hao 江家豪 碩士 國立清華大學 動力機械工程學系 103 This study is focuses on the characteristics of the benzoxazine/epoxy copolymer matrix, combined thegraphene and micro-scale short carbon fibers to be reinforcement. In order to investigate the reinforced mechanism of the nano-scale and micro-scale additive, the interfacial properties, mechanical behavior, and fatigue failure would be realized on the mulit-scale reinforced composite. The researches includes: (1) Different contents of benzoxazine resin in Epoxy resin, (2) graphene and Micro-scale short carbon fibers concentration, (3) the interaction of multi-scale reinforcement material concentration This research aims to discuss the effect of the mixture of nano-scale graphene and micro-scale short carbon fiber, notably intensifies the the mixture of multi-scale interface, improving and increasing both mechanical properties and dynamic fatigue life. The investigation includes:(1)Different Benzoxazine resin concentration in Epoxy,(2)Nano-scale graphene and Micro-scale short carbon fibers concentration.(3)Multi-scale reinforcement material concentration. In the matrix experiment, the results indicate that the value of mechanical strength increases with the content of benzoxazine increased. From the results, the 20wt% benzoxazine/epoxy significantly improves the mechanical strength up to 21.37% improvement in tensile strength; 33.45% improvement in flexural strength; 13.86% improvement in flexural modulus; 38.03% improvement in resistance of water absorption. However, because of the property benzoxazine is more brittle than epoxy, the impact strength of benzoxazine/epoxy copolymer reduces about 55%. The research shows that addition of graphene in the optimum content of 20wt% benzoxazine/epoxy composite 14.18% improvement in tensile strength, 22.83% improvement in the resistance of water absorption by adding the 0.5wt% graphene; 2.46% improvement in flexural strength, and 8.05% improvement in flexural modulus by adding the 0.25wt% graphene. It is showed that adding 8wt% micro-scale short carbon fiber has the best enhancement to the mechanical properties: increasing 22.93% in flexural strength and 9.84% in the resistance of water absorption. Finally, the optimum content of GNPs-0.5wt%/SF-8wt%/ Benzoxazine/ Epoxy composites preform the best enhancement to the properties about 22.62% improvement in tensile strength, 12.2% improvement in flexural strength, and 39.07% improvement in impact strength, 3.2-3.8 times improvement in torsion fatigue life. Because of the reason of short carbon fiber will produce a lot of micro-cracks in the fiber-end, the stress concentration would influence the ductility and lead to cracks propagation. In the result, the flexural tests reveal about 33.84% downtrend in flexural modulus. Yip, Ming-Chuen 葉銘泉 2015 學位論文 ; thesis 116 zh-TW |
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碩士 === 國立清華大學 === 動力機械工程學系 === 103 === This study is focuses on the characteristics of the benzoxazine/epoxy copolymer matrix, combined thegraphene and micro-scale short carbon fibers to be reinforcement. In order to investigate the reinforced mechanism of the nano-scale and micro-scale additive, the interfacial properties, mechanical behavior, and fatigue failure would be realized on the mulit-scale reinforced composite. The researches includes: (1) Different contents of benzoxazine resin in Epoxy resin, (2) graphene and Micro-scale short carbon fibers concentration, (3) the interaction of multi-scale reinforcement material concentration
This research aims to discuss the effect of the mixture of nano-scale graphene and micro-scale short carbon fiber, notably intensifies the the mixture of multi-scale interface, improving and increasing both mechanical properties and dynamic fatigue life. The investigation includes:(1)Different Benzoxazine resin concentration in Epoxy,(2)Nano-scale graphene and Micro-scale short carbon fibers concentration.(3)Multi-scale reinforcement material concentration.
In the matrix experiment, the results indicate that the value of mechanical strength increases with the content of benzoxazine increased. From the results, the 20wt% benzoxazine/epoxy significantly improves the mechanical strength up to 21.37% improvement in tensile strength; 33.45% improvement in flexural strength; 13.86% improvement in flexural modulus; 38.03% improvement in resistance of water absorption.
However, because of the property benzoxazine is more brittle than epoxy, the impact strength of benzoxazine/epoxy copolymer reduces about 55%.
The research shows that addition of graphene in the optimum content of 20wt% benzoxazine/epoxy composite 14.18% improvement in tensile strength, 22.83% improvement in the resistance of water absorption by adding the 0.5wt% graphene; 2.46% improvement in flexural strength, and 8.05% improvement in flexural modulus by adding the 0.25wt% graphene.
It is showed that adding 8wt% micro-scale short carbon fiber has the best enhancement to the mechanical properties: increasing 22.93% in flexural strength and 9.84% in the resistance of water absorption.
Finally, the optimum content of GNPs-0.5wt%/SF-8wt%/ Benzoxazine/ Epoxy composites preform the best enhancement to the properties about 22.62% improvement in tensile strength, 12.2% improvement in flexural strength, and 39.07% improvement in impact strength, 3.2-3.8 times improvement in torsion fatigue life. Because of the reason of short carbon fiber will produce a lot of micro-cracks in the fiber-end, the stress concentration would influence the ductility and lead to cracks propagation. In the result, the flexural tests reveal about 33.84% downtrend in flexural modulus.
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author2 |
Yip, Ming-Chuen |
author_facet |
Yip, Ming-Chuen Juang, Jia-Hao 江家豪 |
author |
Juang, Jia-Hao 江家豪 |
spellingShingle |
Juang, Jia-Hao 江家豪 Investigation on Mechanical Properties and Fracture Behavior by Nanoscale Graphene Discontinuous Carbon Fiber Reinforced Copolymer (Epoxy/Benzoxazine) Composite |
author_sort |
Juang, Jia-Hao |
title |
Investigation on Mechanical Properties and Fracture Behavior by Nanoscale Graphene Discontinuous Carbon Fiber Reinforced Copolymer (Epoxy/Benzoxazine) Composite |
title_short |
Investigation on Mechanical Properties and Fracture Behavior by Nanoscale Graphene Discontinuous Carbon Fiber Reinforced Copolymer (Epoxy/Benzoxazine) Composite |
title_full |
Investigation on Mechanical Properties and Fracture Behavior by Nanoscale Graphene Discontinuous Carbon Fiber Reinforced Copolymer (Epoxy/Benzoxazine) Composite |
title_fullStr |
Investigation on Mechanical Properties and Fracture Behavior by Nanoscale Graphene Discontinuous Carbon Fiber Reinforced Copolymer (Epoxy/Benzoxazine) Composite |
title_full_unstemmed |
Investigation on Mechanical Properties and Fracture Behavior by Nanoscale Graphene Discontinuous Carbon Fiber Reinforced Copolymer (Epoxy/Benzoxazine) Composite |
title_sort |
investigation on mechanical properties and fracture behavior by nanoscale graphene discontinuous carbon fiber reinforced copolymer (epoxy/benzoxazine) composite |
publishDate |
2015 |
url |
http://ndltd.ncl.edu.tw/handle/k9985k |
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