The Mode I interlaminar fracture toughness of chemically carbon nanotube grafted glass fabric/epoxy multi-scale composite structures

2014 ◽  
Vol 63 ◽  
pp. 94-102 ◽  
Author(s):  
Volkan Eskizeybek ◽  
Ahmet Avci ◽  
Ahmet Gülce
Keyword(s):  
Fracture Toughness ◽  
Carbon Nanotube ◽  
Composite Structures ◽  
Glass Fabric ◽  
Mode I ◽  
Interlaminar Fracture Toughness ◽  
Interlaminar Fracture ◽  
Multi Scale

scholarly journals Mixed-Mode Interlaminar Fracture Toughness of Glass and Carbon Fibre Powder Epoxy Composites—For Design of Wind and Tidal Turbine Blades

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2103
Author(s):  
Christophe Floreani ◽  
Colin Robert ◽  
Parvez Alam ◽  
Peter Davies ◽  
Conchúr M. Ó. Brádaigh
Keyword(s):  
Fracture Toughness ◽  
Carbon Fibre ◽  
Composite Structures ◽  
Mixed Mode ◽  
Epoxy Composites ◽  
Mode I ◽  
Mode Ii ◽  
Pure Mode ◽  
Interlaminar Fracture Toughness ◽  
Interlaminar Fracture

Powder epoxy composites have several advantages for the processing of large composite structures, including low exotherm, viscosity and material cost, as well as the ability to carry out separate melting and curing operations. This work studies the mode I and mixed-mode toughness, as well as the in-plane mechanical properties of unidirectional stitched glass and carbon fibre reinforced powder epoxy composites. The interlaminar fracture toughness is studied in pure mode I by performing Double Cantilever Beam tests and at 25% mode II, 50% mode II and 75% mode II by performing Mixed Mode Bending testing according to the ASTM D5528-13 test standard. The tensile and compressive properties are comparable to that of standard epoxy composites but both the mode I and mixed-mode toughness are shown to be significantly higher than that of other epoxy composites, even when comparing to toughened epoxies. The mixed-mode critical strain energy release rate as a function of the delamination mode ratio is also provided. This paper highlights the potential for powder epoxy composites in the manufacturing of structures where there is a risk of delamination.

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.

Double Cantilever Beam Measurement and Finite Element Analysis of Cryogenic Mode I Interlaminar Fracture Toughness of Glass-Cloth/Epoxy Laminates

2000 ◽  
Vol 123 (2) ◽  
pp. 191-197 ◽  
Author(s):  
Y. Shindo ◽  
K. Horiguchi ◽  
R. Wang ◽  
H. Kudo
Keyword(s):  
Fracture Toughness ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Cantilever Beam ◽  
Double Cantilever Beam ◽  
Mode I ◽  
Interlaminar Fracture Toughness ◽  
Element Analysis ◽  
Interlaminar Fracture ◽  
Delamination Crack

An experimental and analytical investigation in cryogenic Mode I interlaminar fracture behavior and toughness of SL-E woven glass-epoxy laminates was conducted. Double cantilever beam (DCB) tests were performed at room temperature (R.T.), liquid nitrogen temperature (77 K), and liquid helium temperature (4 K) to evaluate the effect of temperature and geometrical variations on the interlaminar fracture toughness. The fracture surfaces were examined by scanning electron microscopy to verify the fracture mechanisms. A finite element model was used to perform the delamination crack analysis. Critical load levels and the geometric and material properties of the test specimens were input data for the analysis which evaluated the Mode I energy release rate at the onset of delamination crack propagation. The results of the finite element analysis are utilized to supplement the experimental data.

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