Interfacial Treatment of Multi-Layer Woven Silk Reinforced Epoxy Composites

2010 ◽  
Vol 97-101 ◽  
pp. 1697-1700
Author(s):  
Zulkifli R. ◽  
Che Husna Azhari
Keyword(s):  
Surface Treatment ◽  
Coupling Agent ◽  
Processing Technique ◽  
Epoxy Composites ◽  
Composite Panel ◽  
Silk Fibre ◽  
Interlaminar Fracture ◽  
Fibre Bridging ◽  
Study Test ◽  
Composites Panel

The aim of the project is to study the interlaminar fracture toughness, GIC of woven silk reinforced epoxy composite. Silk fibre has been treated with silane coupling agent and the silk/epoxy composites has been fabricated with different number of silk fibre layers. The processing technique used to prepare the sample is a vacuum bag cured in an autoclave. In this study, test specimens were fabricated by using silk fibre of between 8 to 14 layers. The first set of composites panel consisted of plain silk fibre while the second sets consisted of silk fibre which has been treated with 3-aminopropyl triethoxysilane. Mode I test based on double cantilever beam specimens (DCB) method have been used over all the specimens. The results of the GIC were plotted and compared. GIC of the composites in set 2 were found to be higher than the value in set 1. During the test, crack propagation is stable and no fibre bridging occurred between both sides of fracture surfaces. All the failure that occurred were at the fibre-matrix interface as seen using SEM. The GIC of woven silk/epoxy composites can be enhanced by surface treatment using coupling agent. Surface treatment and number of woven silk fibre layers has affected the interlaminar fracture properties of the composite panel.

Effect of Silane Concentrations on Mode I Interlaminar Fracture of Woven Silk/Epoxy Composites

2010 ◽  
Vol 150-151 ◽  
pp. 1171-1175 ◽  
Author(s):  
Zulkifli R. ◽  
Che Husna Azhari
Keyword(s):  
Fracture Toughness ◽  
Surface Treatment ◽  
Processing Technique ◽  
Epoxy Composites ◽  
Composite Panel ◽  
Mode I ◽  
Silk Fibre ◽  
Interlaminar Fracture Toughness ◽  
Interlaminar Fracture ◽  
Fibre Bridging

The aim of the project is to study the effect of silane concentrations on the interlaminar fracture toughness, GIC of silk/epoxy composites. Woven silk fibre has been treated with five different silane concentrations and fabricated into a panel with two layers of silk fibre. The processing technique used to prepare the sample is by a vacuum bag in an autoclave. Six sets of panels were fabricated based on different 3-aminopropyl triethoxysilane silane concentrations which include one sets of specimens without treatment for comparison. Mode I test based on double cantilever beam specimens (DCB) method has been used over all the specimens. The results of the GIC were plotted and compared with the untreated composites panel. GIC of the composite has been found to increase when the silane concentrations exceeded certain minimum silane contents of 15 ml. During the test, crack propagation is stable and no fibre bridging occurred between both sides of fracture surfaces. All the failure that occurred were at the fibre-matrix interface. The GIC of woven silk/epoxy composites can be enhanced by surface treatment using coupling agent. Surface treatment has affected the properties of the composite panel by increasing the interlaminar fracture toughness by a maximum of 53% at a 5.8vol% silane concentrations.

scholarly journals Mode II Interlaminar Fracture Properties of Treated Silk Fibre/ Epoxy Composites at Low and High Temperature Range

2018 ◽  
Vol 7 (3.17) ◽  
pp. 129
Author(s):  
Rozli Zulkifl ◽  
Che Husna Azhari
Keyword(s):  
Composite Materials ◽  
Crack Propagation ◽  
Surface Treatment ◽  
Mode Ii ◽  
Silk Fibre ◽  
Thermal Imager ◽  
Thermal Coefficient ◽  
Fracture Properties ◽  
Interlaminar Fracture ◽  
Silane Coupling

Composite materials have a wide range of applications including as an automotive components. In certain applications it is exposed to various heat conditions and might affect its mechanical properties. It is important to be able to predict the behavior of the composites under different temperature settings in order to prevent failure. The GIIC properties of composite epoxy laminate with silk fibre at various temperatures have yet to be investigated by any researcher. This study was carried out to analyse the Mode II interlaminar fracture properties, GIIC of the silk fibre / epoxy composite materials when treated with silane coupling agents at different test temperatures. This property is important since it provides the measure of the material’s resistance to delamination crack propagation. Composite specimens were produced using compression moulding technique with sixteen layers of silk fabric. The matrix is an epoxy D.E.R 331 and Hardener Joint mine 905-3S. The weight ratio of mixing epoxy and hardener is 2:1. Six sets of sample were prepared using silk fibre which has undergone surface treatment for 24 hour using silane coupling agent surface treatment solution. Specimens were tested by Instron Universal Testing Machine using a three-point bending based on an end notched flexural (ENF) method. The tests were carried out at six different temperatures which are at 20 oC, 23 oC, 26 oC, 38 oC, 50 oC and 75 oC. The temperature of the specimens during testing was monitored using a thermal imager in order determine the exact test temperature. It was found that as the temperatures increases, the mode II fracture toughness decreases by up to 71%. The length of crack propagation shows that higher temperature leads to longer crack length. This could be due to the residual tension between the fibre and matrix as they have different thermal coefficient of expansion.     

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.

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