The Inter-Laminar Fracture and Mechanical Behavior of Nano-Alumina Modified Glass Fiber/ Epoxy Composite

2012 ◽  
Author(s):  
Mathew John ◽  
Raghu V. Prakash ◽  
Raman Velmurugan
Keyword(s):  
Fracture Toughness ◽  
Glass Fiber ◽  
Epoxy Resin ◽  
Mode I ◽  
Mode Ii ◽  
Glass Fiber Reinforced ◽  
Nano Alumina ◽  
Alumina Particles ◽  
Laminar Fracture ◽  
Modified Epoxy

This paper presents the effect of addition of nano-alumina particles on the fracture properties of glass fiber reinforced plastic (GFRP) composite laminates. Epoxy resin is the most commonly used polymer matrix for advanced composite materials in view of its ability to adhere to a wide variety of fillers; on curing, they provide excellent stiffness and dimensional stability. However the highly cross linked epoxy often behaves undesirably brittle, because, plastic deformation is constrained, leading to poor resistance to crack initiation and propagation. Hence it is necessary to improve the toughness without sacrificing the other important mechanical and thermal properties. In this work, glass-fiber-reinforced composite with nano-alumina modified epoxy matrix was successfully produced with a hand lay-up process and characterized by EDAX and XRD technique for its composition. The experimental results show that the composites exhibited improvements in inter-laminar toughness values (GIC and GIIC) along with improvements in other mechanical properties, especially in toughness related properties. The Mode-I interlaminar fracture toughness for 2 phr (per hundred gram resin) nano-alumina was 2.5 times higher than that of unfilled epoxy and the Mode-II inter-laminar fracture toughness improved by 37%. The significant increase in Mode-I fracture toughness and improvement in Mode II inter-laminar fracture toughness resulting from the nano-particle modification, indicates a pronounced increase in matrix toughness. Impact tests suggest that the energy absorption capability of the GFRP considerably improved with the addition of equi-axed nano-alumina particles with epoxy resin. The laminate and fracture surface morphology analysis was done to understand the fracture and toughening mechanisms behind these property changes. The bending characteristic such as ILSS and Flexural properties recorded the maximum improvements of 14% and 17% respectively for the laminate with nano-alumina modified epoxy. A significant improvement in flexural modulus of over 37% was noticed with respect to unmodified epoxy. The experimental results show that the tensile modulus exhibited 15% improvement compared to laminate without nano-alumina, while, a modest change was observed in the tensile strength.

scholarly journals Woven Glass Fiber Composites with Aligned Carbon Nanotube Sheet Interlayers

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Hardik Bhanushali ◽  
Philip D. Bradford
Keyword(s):  
Fracture Toughness ◽  
Glass Fiber ◽  
Mode I ◽  
Mode Ii ◽  
Interlaminar Fracture Toughness ◽  
Fiber Reinforced ◽  
Interlaminar Fracture ◽  
Glass Fiber Reinforced ◽  
Short Beam ◽  
Woven Glass Fiber

This investigation describes the design, fabrication, and testing of woven glass fiber reinforced epoxy matrix laminates with aligned CNT sheets integrated between plies in order to improve the matrix dominated through thickness properties such as the interlaminar fracture toughness at ply interfaces. Using aligned CNT sheets allows for a concentration of millimeter long CNTs at the most likely point of laminate failure. Mode I and Mode II interlaminar fracture toughness of various CNT modified samples were investigated using double cantilever beam (DCB) and end notched flexure (ENF) experiments, respectively. Short beam strength (SBS) and in-plane tensile properties of the CNT modified samples were also investigated. Moderate improvement was observed in Mode I and Mode II fracture toughness at crack initiation when aligned CNT sheets with a basis weight of 0.354 g/m2were used to modify the ply interface. No compromise in the in-plane mechanical properties of the laminate was observed and very little improvement was observed in the shear related short beam strength of the CNT modified laminates as compared to the control samples. Integration of aligned CNT sheets into the composite laminate imparted in-plane and through thickness electrical properties into the nonconductive glass fiber reinforced epoxy composite laminates.

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.

Seawater effects on interlaminar fracture toughness of glass fiber/epoxy laminates modified with multiwall carbon nanotubes

2020 ◽  
pp. 002199832095078
Author(s):  
Julio A Rodríguez-González ◽  
Carlos Rubio-González
Keyword(s):  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Glass Fiber ◽  
Composite Laminates ◽  
Multiwall Carbon Nanotubes ◽  
Mode I ◽  
Mode Ii ◽  
Interlaminar Fracture Toughness ◽  
Multiscale Composite ◽  
Multiwall Carbon

In this work, the effect of seawater ageing on mode I and mode II interlaminar fracture toughness ([Formula: see text] and [Formula: see text]) of prepreg-based woven glass fiber/epoxy laminates with and without multiwall carbon nanotubes (MWCNTs) has been investigated. The first part of the investigation reports the moisture absorption behavior of multiscale composite laminates exposed to seawater ageing for ∼3912 h at 70 °C. Then, the results of mode I and mode II fracture tests are presented and a comparison of [Formula: see text] and [Formula: see text] for each type of material group and condition is made. Experimental results showed the significant effect of seawater ageing on [Formula: see text] of multiscale composite laminates due to matrix plasticization and fiber bridging. The improvement in [Formula: see text] of the wet glass fiber/epoxy laminate was about 50% higher than that of the neat laminate (without MWCNTs) under dry condition. It was also found that the presence of MWCNTs into composite laminates promotes a moderate increase (8%) in their [Formula: see text] as a result of the additional toughening mechanisms induced by CNTs during the delamination process. Scanning electron microscopy analysis conducted on fracture surface of specimens reveals the transition from brittle (smooth surface) to ductile (rough surface) in the morphology of composite laminates due to the influence of seawater ageing on the polymeric matrix and fiber/matrix interface.

Effect of Carbon Milled Fiber Addition on Interlaminar Fracture Toughness of Carbon Fiber Reinforced Plastics

2013 ◽  
Vol 577-578 ◽  
pp. 73-76 ◽  
Author(s):  
Hideaki Katogi ◽  
Kenichi Takemura
Keyword(s):  
Fracture Toughness ◽  
Carbon Fiber ◽  
Epoxy Resin ◽  
Mode I ◽  
Mode Ii ◽  
Interlaminar Fracture Toughness ◽  
Interlaminar Fracture ◽  
Carbon Fiber Reinforced Plastics ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics

In this study, effect of Carbon Milled Fiber (CMF) addition on interlaminar fracture toughness of carbon fiber reinforced plastics (CFRP) was investigated. Plain woven carbon fiber was used as reinforcement. Epoxy resin was used as matrix. The addition amounts of CMF are 0.5wt%, 0.8wt%, 1.0wt% and 1.2wt% for the epoxy resin. Mode I and mode II interlaminar fracture toughness tests were conducted based on JIS K 7086. As a result, mode I and mode II interlaminar fracture toughness increased with an increase of addictive amount of CMF. But excess addition was not effective. Pull out of CMF in matrix was found after mode I and mode II interlaminar fracture toughness tests. The mode I and mode II interlaminar fracture toughness of CMF added CFRP can be improved by fiber bridging of CMF.

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.

Mode I Fracture Toughness of Banana Fiber and Glass Fiber Reinforced Composites

2012 ◽  
Vol 622-623 ◽  
pp. 1320-1324
Author(s):  
V. Santhanam ◽  
M. Chandrasekaran ◽  
N. Venkateshwaran ◽  
A. Elayaperumal
Keyword(s):  
Fracture Toughness ◽  
Glass Fiber ◽  
Volume Fraction ◽  
Fiber Reinforced Polymers ◽  
Mode I ◽  
Fiber Reinforced ◽  
Banana Fiber ◽  
Mode I Fracture ◽  
Mode I Fracture Toughness ◽  
Glass Fiber Reinforced

Although fiber-reinforced polymers (FRP) have until now been largely applied to various fields of engineering, these materials have also been used in many technical applications, especially where high strength and stiffness are required, but with low component weight. Among various natural fibers, banana fiber is of particular interest in that its composites have high tensile strength, high tensile modulus, and low elongation at break beside its low cost and eases of availability. In this study, banana fiber and glass fiber reinforced polyester Resin composites were prepared using hand lay up technique . Experiments are conducted to compare and to find the effect of fiber volume fraction on mode I fracture toughness of both composites.

scholarly journals Influence of Milled Glass Fiber Fillers on Mode I & Mode II Interlaminar Fracture Toughness of Epoxy Resin for Fabrication of Glass/Epoxy Composites

Fibers ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 36
Author(s):  
Kannivel Saravanakumar ◽  
Vellayaraj Arumugam ◽  
Rotte Souhith ◽  
Carlo Santulli
Keyword(s):  
Fracture Toughness ◽  
Glass Fiber ◽  
Composite Laminates ◽  
Glass Fibers ◽  
Mode I ◽  
Mode Ii ◽  
Additional Energy ◽  
Maximal Increase ◽  
Mode Ii Fracture Toughness ◽  
Delamination Resistance

The present work is focused on improving mode I and mode II delamination resistance of glass/epoxy composite laminates (50 wt.% of glass fibers) with milled glass fibers, added in various amounts (2.5, 5, 7.5 and 10% of the epoxy weight). Including fillers in the interlayer enhances the delamination resistance by providing a bridging effect, therefore demanding additional energy to initiate the crack in the interlaminar domain, which results in turn in enhanced fracture toughness. The maximal increase of mode I and mode II fracture toughness and of flexural strength was obtained by the addition of 5% milled glass fiber. The mechanism observed suggests that crack propagation is stabilized even leading to its arrest/deflection, as a considerable amount of milled glass fiber filler was oriented transverse to the crack path. In contrast, at higher filler loading, tendency towards stress concentration grows due to local agglomeration and improper dispersion of excess fillers in inter/intralaminar resin channel, causing poor adhesion to the matrix, which leads to reduction in fracture toughness, strength and strain to failure. Fractured surfaces analyzed using scanning electron microscopy (SEM) revealed a number of mechanisms, such as crack deflection, individual debonding and filler/matrix interlocking, all contributing in various ways to improve fracture toughness.

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