Dynamic 4 ENF test for a strain rate dependent mode II interlaminar fracture toughness characterization of unidirectional carbon fibre epoxy composites

2016 ◽  
Vol 55 ◽  
pp. 212-218 ◽  
Author(s):  
H. Zabala ◽  
L. Aretxabaleta ◽  
G. Castillo ◽  
J. Aurrekoetxea
Keyword(s):  
Fracture Toughness ◽  
Carbon Fibre ◽  
Strain Rate ◽  
Epoxy Composites ◽  
Mode Ii ◽  
Interlaminar Fracture Toughness ◽  
Interlaminar Fracture ◽  
Rate Dependent ◽  
Enf Test

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.

scholarly journals Effect of sewage sludge ash filler on mode I and mode II interlaminar fracture toughness of S-glass/epoxy composites

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Mohamad Alsaadi 1,2 ◽  
Ahmet Erkliğ 2
Keyword(s):  
Fracture Toughness ◽  
Sewage Sludge ◽  
Epoxy Composites ◽  
Mode I ◽  
Mode Ii ◽  
Interlaminar Fracture Toughness ◽  
Sewage Sludge Ash ◽  
Interlaminar Fracture ◽  
Glass Fiber Reinforced ◽  
Sludge Ash

In this study, the influence of sewage sludge ash (SSA) waste particle contents on the mechanical properties and interlaminar fracture toughness for mode I and mode II delamination of S-glass fiber reinforced epoxy composites were investigated. Composite laminate specimens for tensile, flexural double-cantilever beam (DCB) and end-notched flexure (ENF) tests were prepared and tested according to ASTM standards with 5, 10, 15 and 20 wt% SSA filled S-glass/epoxy composites. Properties improvement reasons was explained based on optical and scanning electron microscopy. The highest improvement in tensile and flexural strength was obtained with 10 wt% content of SSA. The highest mode I and mode II interlaminar fracture toughness’s were obtained with 15 wt% content of SSA. The mode I and mode II interlaminar fracture toughness’s improved by 33 and 63.6%, respectively, compared to the composite without SSA.

Delamination Behaviour of Rubber-Toughened Carbon Fibre/Epoxy Composites

2013 ◽  
Vol 392 ◽  
pp. 73-77
Author(s):  
Helen Wu
Keyword(s):  
Fracture Toughness ◽  
Plastic Zone ◽  
Carbon Fibre ◽  
Composite Laminates ◽  
Epoxy Composites ◽  
Interlaminar Fracture Toughness ◽  
Interlaminar Fracture ◽  
The Matrix ◽  
Key Factor ◽  
Modified Epoxy

In this study, core-shell rubber (CSR) and liquid rubber (LR) were used to modify the matrix toughness of unidirectional carbon fibre/epoxy composites. Double cantilever beam (DCB) and end notched flexure (END) tests were performed to evaluate the interlaminar fracture toughness. It was found that LR was identified to be more effective than CSR in improving GICand GIICof the composites, although fracture toughness of the CSR-modified epoxy was better than that of the LR-modified epoxy. SEM observation of post-fracture surfaces of the specimens shows that the degree of plastic deformation of matrix is well related to the rating of fracture toughness of composites for these unmodified and modified composite laminates, and is the key factor controlling the interlaminar fracture toughness of composite laminates. Further, it was confirmed that rigid fibres constrain growth of plastic zone in composites laminates, comparing with toughened bulk epoxy matrix. However, plastic zone is not limited to a single resin layer and it is capable of developing across rigid fibre layers.

Interlaminar fracture toughness of flax-epoxy composites

2016 ◽  
Vol 36 (2) ◽  
pp. 121-136 ◽  
Author(s):  
F Bensadoun ◽  
I Verpoest ◽  
AW Van Vuure
Keyword(s):  
Fracture Toughness ◽  
Epoxy Composite ◽  
Flax Fibre ◽  
Epoxy Composites ◽  
Mode I ◽  
Mode Ii ◽  
Interlaminar Fracture Toughness ◽  
Interlaminar Fracture ◽  
Brittle Polymer ◽  
Tensile Toughness

The purpose of this study was to determine the influence of fibre architectures on the interlaminar fracture toughness and tensile toughness of flax fibre epoxy composites. The fracture toughness was investigated for both Mode I (GIC) and Mode II (GIIC) for seven flax-epoxy architectures: one plain weave, two twill 2 × 2 weaves, a quasi-unidirectional and a unidirectional architecture, the UD’s being tested in both [0,90] and [90,0] composite lay-ups. The results of the Mode I and Mode II showed promising results of the flax-epoxy composite performance. The addition of flax fibre increases the GIC and GIIC of the composites over that of the unreinforced brittle polymer by at least two to three times. Further improvements are made with the use of woven textiles. The tensile toughness was found to be a good indicator of the capacity of a material to sustain perforation or non-perforation impact.

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