scholarly journals Experimental Method for Tensile Testing of Unidirectional Carbon Fibre Composites Using Improved Specimen Type and Data Analysis

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3939
Author(s):  
Rajnish Kumar ◽  
Lars P. Mikkelsen ◽  
Hans Lilholt ◽  
Bo Madsen
Keyword(s):  
Data Analysis ◽  
Carbon Fibre ◽  
Experimental Method ◽  
Tensile Testing ◽  
Fibre Composite ◽  
Specimen Geometry ◽  
Carbon Composites ◽  
Stress Strain ◽  
Fibre Composites ◽  
Carbon Fibre Composites

This paper presents an experimental method for tensile testing of unidirectional carbon fibre composites. It uses a novel combination of a new specimen geometry, protective layer, and a robust data analysis method. The experiments were designed to test and analyze unprotected (with conventional end-tabs) and protected (with continuous end-tabs) carbon fibre composite specimens with three different specimen geometries (straight-sided, butterfly, and X-butterfly). Initial stiffness and strain to failure were determined from second-order polynomial fitted stress–strain curves. A good agreement between back-calculated and measured stress–strain curves is found, on both composite and fibre level. For unprotected carbon composites, the effect of changing specimen geometry from straight-sided to X-butterfly was an increase in strain to failure from 1.31 to 1.44%. The effect of protection on X-butterfly specimens was an increase in strain to failure from 1.44 to 1.53%. For protected X-butterfly specimens, the combined effect of geometry and protection led to a significant improvement in strain to failure of 17% compared to unprotected straight-sided specimens. The observed increasing trend in the measured strain to failure, by changing specimen geometry and protection, suggests that the actual strain to failure of unidirectional carbon composites is getting closer to be realized.

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%).

Incremental Damage Development in a 3D Woven Carbon Fibre Composite

2007 ◽  
Vol 15 (7) ◽  
pp. 521-533
Author(s):  
S. King ◽  
G. Stewart ◽  
A.T. McIlhagger ◽  
J.P. Quinn
Keyword(s):  
Carbon Fibre ◽  
Fibre Composite ◽  
Weight Ratio ◽  
Matrix Cracking ◽  
Limiting Factors ◽  
Damage Development ◽  
Carbon Fibre Composite ◽  
Damage Initiation ◽  
Fibre Composites ◽  
Carbon Fibre Composites

Interest in 3D woven carbon fibre composites has increased within industries such as aerospace, automotive and marine, due to their high strength to weight ratio, their increased tailorability and their capacity to be manufactured into near net shape preforms, thereby reducing parts count, assembly time, labour intensity and costs. It is vital that critical areas of concern such as damage (and in particular damage initiation and development) are studied and understood, thereby reducing the limiting factors to their acceptance. The damage initiation and subsequent intervals of development for ILSS (Interlaminar Shear Strength) were determined experimentally. Particular focus is paid to the significance of binder edge and binder middle testing and the influence of through-the-thickness (T-T-T) reinforcement in relation to damage types and development. Control samples for binder edge and binder middle loading locations were tested to failure as a means of determining an average point of failure, allowing the generation of testing intervals. The performance and architecture of samples from each incremental interval were characterised using a combination of graphical analysis and optical microscopy with the aid of dye-penetrant to highlight fibre damage and matrix cracking. Samples displayed specific damage initiation points, thus allowing the generation of a damage guide relating to applied force. In addition, the results imply that a relationship exists between the location of applied load and subsequent damage, thus showing the significant influence played by the T-T-T binder loading location on damage development within 3D woven carbon fibre composites. Some of the preliminary data shown in this paper was presented at IMC23 at the University of Ulster, UK in August 2006 and at Texcomp 8 in Nottingham, UK October 2006.

scholarly journals Carbon Fibre-Copper Composites Made by Volumetric Bonding.

1993 ◽  
Vol 2 (6) ◽  
pp. 096369359300200 ◽  
Author(s):  
W. Włosinski ◽  
D. Kalinski ◽  
W. Olesinska ◽  
K. Pietrzak
Keyword(s):  
Carbon Fibre ◽  
Fibre Composite ◽  
New Method ◽  
Carbon Fibre Composite ◽  
Fibre Composites ◽  
Composite Microstructure ◽  
Carbon Fibre Composites ◽  
Measured Density

Abstract. The results of investigation on forming copper-carbon fibre composite were presented. A new method of vacuum volumetric bonding was elaborated for this purpose. The copper-carbon fibre composites were processed at temperatures between 750 and 1050°C under pressures of 30 to 60 MPa and times ranging from 15 to 60 minutes. The composite microstructure was found to be homogeneous, the measured density varied from 6.58 up to 7.8 g/cm3 and the hardness ranged from 63 to 113 HB (KG/mm2).

scholarly journals An Improved Method for the preparation of High Quality Carbon Fibre Composite Test Bars

1993 ◽  
Vol 2 (6) ◽  
pp. 096369359300200 ◽  
Author(s):  
G F Tudgey
Keyword(s):  
Carbon Fibre ◽  
Fibre Composite ◽  
Improved Method ◽  
Carbon Fibre Composite ◽  
High Quality ◽  
Matrix Polymer ◽  
Fibre Composites ◽  
Carbon Fibre Composites

The properties of carbon fibre composites derived from novel matrix polymers are often required for evaluation. An improved method has been developed to enable the preparation of unidirectional carbon fibre composite test bars of uniform high quality using only small quantities of matrix polymer.

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