Experimental Characterization of Hybrid and Non-Hybrid Polymer Composites at Elevated Temperatures

2018 ◽  
Vol 36 ◽  
pp. 37-52 ◽  
Author(s):  
Getahun Aklilu ◽  
Sarp Adali ◽  
Glen Bright
Keyword(s):  
Mechanical Properties ◽  
Carbon Fibre ◽  
Wind Turbine ◽  
Elevated Temperatures ◽  
Turbine Blades ◽  
Wind Turbine Blades ◽  
Fibre Composites ◽  
Glass Carbon ◽  
Carbon Fibre Composites ◽  
Laminar Shear

Glass and carbon fibre composites and hybrid glass/carbon composites are materials often used in wind turbine blades. In Africa wind turbines have to operate in warm climates. The present study presents the results of an experimental study on the mechanical properties of these composites at elevated temperatures. For this purpose, the composite specimens are fabricated by hand lay-up process to investigate their static and dynamic properties at high temperatures. The properties studied include Inter-laminar Shear Stress (ILSS), Dynamic Mechanical Properties (DMA) such as storage modulus, loss modulus and loss factor using ASTM standards. The inter-laminar shear failure strength of carbon fibre and hybrid glass-carbon fibre composites are found to be close whereas the glass transition and damping behavior of the hybrid composites are higher making them suitable for wind turbine blades operating at high temperatures. Short Beam Shear (SBS) test data are evaluated using chi-square goodness of fit statistical tests and the correlation coefficients from linear regression analysis are determined. Normal, lognormal and 2-parameter Weibull statistical distributions are used at 5% significant level.

Temperature Effect on Mechanical Properties of Carbon, Glass and Hybrid Polymer Composite Specimens

2018 ◽  
Vol 39 ◽  
pp. 119-138 ◽  
Author(s):  
Getahun Aklilu ◽  
Sarp Adali ◽  
Glen Bright
Keyword(s):  
Mechanical Properties ◽  
Wind Turbine ◽  
Shear Failure ◽  
Elevated Temperatures ◽  
Turbine Blades ◽  
Wind Farms ◽  
Mechanical Analysis ◽  
Experimental Results ◽  
Experimental Program ◽  
Laminar Shear

This paper presents the results of an experimental program to study the mechanical properties of currently available composite materials for the construction of wind turbine blade. The materials identified for this purpose include unidirectional glass fibre/epoxy (GFRP), carbon fibre/epoxy (CFRP) and hybrid combinations of these two materials to be used in a laminated design and at elevated temperatures. The tests conducted in the present programme includes short beam shear test and dynamic mechanical analysis tests after the specimens are exposed to temperatures ranging from 25 to 140°C. The results indicate that the inter-laminar shear failure strength and stiffness of GFRP, CFRP and hybrid specimens degrade with increasing temperature. However, the degradation is observed to be higher in single material specimens in comparison to hybrid specimens. In particular, stiffness of CFRP specimens decreased linearly as the temperature approached 40°C and increased up to the glass transition temperature of epoxy. Experimental results indicated that damping properties of Glass-Carbon-Glass/epoxy specimens improved at elevated temperatures which is important for noise and vibration control. In the present study, empirical models are proposed based on the test data to predict the variation of inter-laminar shear failure stress and stiffness as a function of temperature. The experimental results and proposed model can be used as input parameters to design and construct composite wind turbine blades to be used in tropical wind farms.

Hybrid silica micro and PDDA/nanoparticles-reinforced carbon fibre composites

2016 ◽  
Vol 51 (6) ◽  
pp. 783-795 ◽  
Author(s):  
Júlio C Santos ◽  
Luciano MG Vieira ◽  
Túlio H Panzera ◽  
André L Christoforo ◽  
Marco A Schiavon ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Fibre ◽  
Silica Nanoparticles ◽  
Fibre Composite ◽  
Flexural Modulus ◽  
Specific Chemical ◽  
Diallyldimethylammonium Chloride ◽  
Fibre Composites ◽  
Carbon Fibre Composites ◽  
Hybrid Carbon

The work describes the manufacturing and testing of novel hybrid epoxy/carbon fibre composites with silica micro and poly-diallyldimethylammonium chloride-functionalised nanoparticles. A specific chemical dispersion procedure was applied using the poly-diallyldimethylammonium chloride to avoid clustering of the silica nanoparticles. The influence of the various manufacturing parameters, particles loading, and mechanical properties of the different phases has been investigated with a rigorous Design of Experiment technique based on a full factorial design (2131). Poly-diallyldimethylammonium chloride-functionalised silica nanoparticles were able to provide a homogenous dispersion, with a decrease of the apparent density and enhancement of the mechanical properties in the hybrid carbon fibre composites. Compared to undispersed carbon fibre composite laminates, the use of 2 wt% functionalised nanoparticles permitted to increase the flexural modulus by 47% and the flexural strength by 15%. The hybrid carbon fibre composites showed also an increase of the tensile modulus (9%) and tensile strength (5.6%).

Effect of Hybridization on Flexural Performance of Unidirectional and Bidirectional Composite Laminates under Ambient Temperature

2021 ◽  
Vol 56 ◽  
pp. 16-33
Author(s):  
Getahun Aklilu ◽  
Sarp Adali ◽  
Glen Bright
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Carbon Fibre ◽  
Composite Laminates ◽  
Hybrid Composites ◽  
Flexural Modulus ◽  
Turbine Blades ◽  
Carbon Fibres ◽  
Wind Turbine Blades ◽  
Flexural Performance

Abstract. Fibre Reinforced Plastic (FRP) materials are widely used in several key engineering applications such as ships, aircraft, wind turbine blades, helicopter blade, automobiles, and other transportation vehicles because of their mechanical properties and tailoring capabilities.Carbon and glass fibres are the most popular fibre reinforcements used for composite components. In the present study, two different stacking sequences, (0 degrees) and (0/90 degrees), are selected to study effect of fibre hybridization on flexural performance using three-point bending tests. Materials used are E-glass and T-300 carbon fibres in an epoxy matrix and the laminates were produced by resin transfer moulding methods. Fracture surfaces of composite laminates were examined using a scanning electron microscope. The results showed that the flexural strength, modulus and strain at failure of unidirectional and bidirectional composite laminates were strongly influenced by stacking sequences, fibre orientation and the hybrid ratio of the fibres. A higher flexural modulus was achieved when carbon fibres were placed on the compressive side. Hybrid specimens showed higher flexural strength and modulus by 21.08% and 145.39%, respectively, compared to the pure glass fibre reinforced laminates. On the other hand, flexural strength and modulus of hybrid specimen were less by 6.50% and 8.20%, respectively, as compared to carbon fibre reinforced specimens. Stacking sequences and hybrid ratio of glass/carbon fibre reinforced specimens were investigated with a view towards improving the mechanical properties of hybrid composites.

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