Interlaminar Fracture in Carbon Fiber/Thermoplastic Composites

1989 ◽  
Vol 170 ◽  
Author(s):  
J. A. Hinkley ◽  
W. D. Bascom ◽  
R. E. Allred
Keyword(s):  
Fracture Toughness ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
High Strain ◽  
Thermoplastic Composites ◽  
Plasma Modification ◽  
Interlaminar Fracture Toughness ◽  
Interlaminar Fracture ◽  
Polyphenylene Oxide ◽  
Commercial Carbon

AbstractThe surfaces of commercial carbon fibers are generally chemically cleaned or oxidized and then coated with an oligomeric sizing to optimize their adhesion to epoxy matrix resins. Evidence from fractography, from embedded fiber testing and from fracture energies suggests that these standard treatments are relatively ineffective for thermoplastic matrices. This evidence is reviewed and model thermoplastic composites (polyphenylene oxide/high strain carbon fibers) are used to demonstrate how differences in adhesion can lead to a two-fold change in interlaminar fracture toughness.The potential for improved adhesion via plasma modification of fiber surfaces is discussed. Finally, a surprising case of fiber-catalyzed resin degradation is described.

Interlaminar fracture toughness and electromagnetic interference shielding of hybrid-stitched carbon fiber composites

2018 ◽  
Vol 37 (18) ◽  
pp. 1131-1141 ◽  
Author(s):  
Nisrin R Abdelal ◽  
Steven L Donaldson
Keyword(s):  
Fracture Toughness ◽  
Carbon Fiber ◽  
Electromagnetic Interference ◽  
Experimental Results ◽  
Mode I ◽  
Carbon Fiber Composites ◽  
Interlaminar Fracture Toughness ◽  
Shielding Effectiveness ◽  
Electromagnetic Interference Shielding ◽  
Interlaminar Fracture

In the current study, the production of multifunctional hybrid-stitched composites with improved interlaminar fracture toughness and electromagnetic interference shielding effectiveness is reported. Unidirectional carbon fiber-epoxy composite laminates stitched with Kevlar, nylon, hybrid stitched with both Kevlar and nylon and unstitched were prepared using resin infusion process. Representative specimens from unstitched and stitched composites were tested using rectangular waveguide and Mode I double cantilever beam tests. The Mode I experimental results showed that composite stitched with Kevlar exhibited the highest crack initiation interlaminar fracture toughness (GIC-initiation), whereas composite stitched with nylon exhibited the highest maximum crack propagation interlaminar fracture toughness (GIC-maximum). The four-hybrid stitching patterns exhibited higher GIC-initiation than the unstitched and stitched with nylon composites and lower than stitched with Kevlar composite, whereas they had higher GIC-maximum than the unstitched and stitched with Kevlar composites, although lower than stitched with nylon composite. The electromagnetic shielding effectiveness experimental results showed that stitched composites exhibited improved shielding effectiveness compared to unstitched composites. For example, composite stitched with nylon had highest shielding effectiveness value of 52.17 dB compared by the composite stitched with Kevlar which had 40.6 dB. The four hybrid-stitched composites exhibited similar shielding effectiveness with an average value of 32.75 dB compared to the unstitched composite shielding effectiveness of 22.84 dB. The experimental results comply with the initial goal of this study to manufacture multifunctional hybrid stitching composites with combined properties between Kevlar and nylon-stitched composites.

scholarly journals Improved Interlaminar Fracture Toughness and Electrical Conductivity of CFRPs with Non-Woven Carbon Tissue Interleaves Composed of Fibers with Different Lengths

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 803 ◽  
Author(s):  
Feng Xu ◽  
Bo Yang ◽  
Lijie Feng ◽  
Dedong Huang ◽  
Min Xia
Keyword(s):  
Electrical Conductivity ◽  
Fracture Toughness ◽  
Carbon Fibers ◽  
Mode I ◽  
Mode Ii ◽  
Thickness Direction ◽  
Interlaminar Fracture Toughness ◽  
Filtration Method ◽  
Interlaminar Fracture ◽  
Pull Out

Non-woven carbon tissue (NWCT) with different fiber lengths was prepared with a simple surfactant-assistant dispersion and filtration method and used as interleaving to enhance both delamination resistance and electrical conductivity of carbon fiber reinforced plastics (CFRPs) laminates. The toughing effect of NWCT on both Mode I and Mode II interlaminar fracture of CFRPs laminate is dependent on length of fibers, where the shorter carbon fibers (0.8 mm) perform better on Mode I interlaminar fracture toughness improvement whereas longer carbon fibers (4.3 mm) give more contribution to the Mode II interlaminar fracture toughness increase, comparing with the baseline composites, and the toughness increase was achieved without compromising of flexural mechanical properties. More interestingly, comparing with the baseline composites, the electrical conductivity of the interleaved composites exhibited a significant enhancement with in-plane and through-the-thickness direction, respectively. Microscopy analysis of the carbon tissue interleaving area in the laminate indicated that carbon fibers with shorter length can form into a 3D network with more fibers aligned along through-the-thickness direction compared with longer ones. The shorter fibers thus potentially provide more effective fiber bridges, pull-out and matrix deformation during the crack propagation and improve the electric conductivity significantly in through-the-thickness direction.

Investigation of the effect of single wall carbon nanotubes on interlaminar fracture toughness of woven carbon fiber—epoxy composites

2011 ◽  
Vol 45 (10) ◽  
pp. 1091-1107 ◽  
Author(s):  
Piyush R. Thakre ◽  
Dimitris C. Lagoudas ◽  
Jaret C. Riddick ◽  
Thomas S. Gates ◽  
Sarah-Jane V. Frankland ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Carbon Fiber ◽  
Epoxy Composites ◽  
Single Wall Carbon Nanotubes ◽  
Interlaminar Fracture Toughness ◽  
Interlaminar Fracture ◽  
Single Wall Carbon ◽  
Carbon Fiber Epoxy
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