TITLE:
Improvement in Impact Energy Absorption of UD-CFRP by Sub-Micron Glass Fiber into Its Matrix
AUTHORS:
Ryotaro Murayama, Kiyotaka Obunai, Kazuya Okubo, Li Bao
KEYWORDS:
Energy Absorption, Split Hopkinson Pressure Bar Method, Interfacial Shear Strength, Strain Rate
JOURNAL NAME:
Open Journal of Composite Materials,
Vol.11 No.4,
September
13,
2021
ABSTRACT: CFRPs have high
strength despite low density, but little impact resistance. In addition, the
debonding of the interface between reinforcement fiber and matrix causes one of
the fractures of FRPs. Therefore, the purpose of this study is to
investigate the interfacial bonding characteristics between the reinforcement
fiber and matrix of FRPs, not only under static loading but also under dynamic
loading. Moreover, an effective method to improve the impact resistance of FRPs
from the viewpoint of interfacial bonding characteristics was proposed. First,
two types of UD-FRPs in which the reinforcement fiber was glass fiber or carbon fiber, were prepared to investigate the energy absorption under a bending load. A
bending load was applied to the specimen statically and dynamically to measure
the energy absorption until failure. The interfacial bonding characteristics
between the reinforcement fiber and matrix
were measured using a fragmentation method with a single fiber-embedded specimen. A dynamic tensile load was applied to the specimen using a
tensile-type split Hopkinson pressure bar apparatus. Test results showed that
the energy absorption of UD-CFRP decreased with an increase in strain rate,
whereas that of UD-GFRP increased with an increase in strain rate. When the
epoxy resin was modified by adding sub-micron glass fiber, both the interfacial
shear strength between the carbon fiber and matrix, and the energy absorption
of UD-CFRP improved.