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.

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 Enhancement in Mode II Interlaminar Fracture Toughness at Cryogenic Temperature of Glass Fiber/Epoxy Composites through Matrix Modification by Carbon Nanotubes and n-Butyl Glycidyl Ether

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Yu Liu ◽  
Cheng-Bing Qu ◽  
Qing-Ping Feng ◽  
Hong-Mei Xiao ◽  
Shao-Yun Fu
Keyword(s):  
Fracture Toughness ◽  
Glass Fiber ◽  
Glycidyl Ether ◽  
Mode Ii ◽  
Interlaminar Fracture Toughness ◽  
Interlaminar Fracture ◽  
Matrix Modification ◽  
The Matrix ◽  
Butyl Glycidyl Ether ◽  
Modified Epoxy

A typical diglycidyl ether of bisphenol-F (DGEBF)/diethyl toluene diamine (DETD) epoxy system modified by multiwalled carbon nanotubes (MWCNTs) and a reactive aliphatic diluent named n-butyl glycidyl ether (BGE) was used as the matrix for glass fiber composites. The glass fiber (GF) reinforced composites based on the unmodified and modified epoxy matrices were prepared by the hand lay-up hot-press process. Mode II interlaminar fracture toughness at both room temperature (RT) and cryogenic temperature (77 K) of the GF reinforced epoxy composites was investigated to examine the effect of the matrix modification. The result showed that the introduction of MWCNTs and BGE at their previously reported optimal contents led to the remarkable enhancement in mode II interlaminar fracture toughness of the composites. Namely, the 22.9% enhancement at RT and the 31.4% enhancement at 77 K were observed for mode II interlaminar fracture toughness of the fiber composite based on the optimally modified epoxy matrix by MWCNTs and BGE compared to the unmodified case.

Damage development in woven carbon fibre thermoplastic laminates with PPS and PEEK matrices: A comparative study

2016 ◽  
Vol 51 (5) ◽  
pp. 637-647 ◽  
Author(s):  
Sergey G Ivanov ◽  
Dries Beyens ◽  
Larissa Gorbatikh ◽  
Stepan V Lomov
Keyword(s):  
Fracture Toughness ◽  
Carbon Fibre ◽  
Mechanical Performance ◽  
Textile Composites ◽  
Interlaminar Fracture Toughness ◽  
Carbon Fabric ◽  
Interlaminar Fracture ◽  
Peek Composite ◽  
The Matrix ◽  
Carbon Fibre Composites

In this work, we investigate the effect of the matrix on the mechanical performance of woven carbon fibre composites. More specifically, composites with the same 5-harness satin carbon fabric reinforcement and different thermoplastic matrices, PPS and PEEK, are compared in various mechanical tests (tensile, interlaminar fracture toughness and compression-after-impact tests). The results of tension tests show the influence of the matrix type on the development of cracks in yarns. The cracks in carbon fabric/PEEK composite appear later than in carbon fabric/PPS composite. Their density is also lower. A correlation between cumulative acoustic emission energy and transverse crack appearance in tensile tests is shown. The most evident difference is demonstrated for the Double Cantilever Beam tests and End Notch Flexure tests. The interlaminar fracture toughness for both mode I and mode II is more than 1.5 times higher for carbon fabric/PEEK laminates as compared to carbon fabric/PPS ones. The higher fracture toughness of carbon fabric/PEEK results in its higher residual compressive strength after impact (∼25%). Thus, the study concludes that the performance of textile composites is highly sensitive to the performance of the matrix. Matrices that have higher strength, ductility and fracture toughness lead to structural composites with lower crack densities, better performance in the bias direction, higher resistance to delaminations and higher residual strength after impact.

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