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.

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%).

scholarly journals A Time-Frequency Research for Ultrasonic Guided Wave Generated from the Debonding Based on a Novel Time-Frequency Analysis Technique

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Junhua Wu ◽  
Zheshu Ma ◽  
Yonghui Zhang
Keyword(s):  
Carbon Fibre ◽  
Frequency Analysis ◽  
Instantaneous Frequency ◽  
Fibre Composite ◽  
Guided Wave ◽  
Carbon Fibre Composite ◽  
Time Frequency Analysis ◽  
Time Frequency ◽  
Ultrasonic Guided Wave ◽  
Carbon Fibre Composites

Carbon fibre composites have a promising application in the future of the vehicle, because of their high strength and light weight. Debonding is a major defect of the carbon fibre composite. The time-frequency analysis is fundamental to identify the defect on ultrasonic nondestructive evaluation and testing. In order to obtain the instantaneous frequency and the peak time of modes of the ultrasonic guided wave, an algorithm based on the Smoothed Pseudo Wigner-Ville distribution and the peak-track algorithm is presented. In the algorithm, a masking step is proposed, which can guarantee that the peak-track algorithm can automatically exact the instantaneous frequency and the instantaneous amplitude of different modes on the Smoothed Pseudo Wigner-Ville distribution. An experiment for detecting the debonding for a type of carbon fibre composite is done. The presented algorithm is employed on the experimental signals. The processed result of experimental signals reveals that the defect can stimulate new modes, and there is a quantitative relationship between the defect size and the frequency of the new mode. The presented technique provides a valuable way to detect the presentence, calculate the size, and locate the position of the debonding defect.

Experimental Analysis of Tool Wear when Drilling Carbon Fibre Composite (CFC) without Cutting Fluid, with Cutting Fluid and with a Pre-Cryogenically Cooled Tool

2013 ◽  
Vol 372 ◽  
pp. 512-515
Author(s):  
Aishah Najiah Dahnel ◽  
Stuart Barnes ◽  
Pipat Bhudwannachai
Keyword(s):  
Tool Wear ◽  
Carbon Fibre ◽  
Fibre Composite ◽  
Cutting Speed ◽  
Cryogenic Cooling ◽  
Cutting Fluid ◽  
Heterogeneous Structure ◽  
Carbon Fibre Composite ◽  
Dry Drilling ◽  
Carbon Fibre Composites

Machining of Carbon Fibre Composites (CFCs) particularly drilling, is frequently employed in industry especially when dealing with joining, assembly and structural repair of the parts. However, the nature and heterogeneous structure of CFCs often results in rapid wear of the cutting tool. This research studied the relationship and compared the effect of drilling a CFC plaque without cutting fluid, with conventional cutting fluid and with cryogenic cooling at constant cutting speed of 94 m/min and feed rate of 0.065 mm/revolution using tungsten carbide twist drill. The conventional cutting fluid was supplied continuously to the drill and the CFC plaque during the drilling cycle; while for the cryogenic cooling tests, the drill tip was immersed in liquid nitrogen for 10 and 30 seconds prior to drilling the CFC. It was found that the tool wear increased with the increasing number of drilled holes at all machining conditions. After drilling of 325 holes, the largest tool wear observed was 181 μm which was produced when drilling the CFC plaque with conventional cutting fluid. The corresponding tool wear for drilling with cryogenic cooling was 164 μm and the smallest tool wear of 155 μm was observed during dry drilling. Dry drilling produced the smallest tool wear because the heat generated reduced the strength of the CFC, particularly polymer matrix. Therefore, this situation led to easier machining of CFC materials; consequently reduced the wear of the tool.

Progressive damage analysis of adhesively bonded patch repaired carbon fibre–reinforced polymer specimen under compression involving cohesive zone model

2019 ◽  
Vol 28 (10) ◽  
pp. 1457-1489 ◽  
Author(s):  
Seshadri Matta ◽  
Naresh Reddy Kolanu ◽  
Viswanath Chinthapenta ◽  
C M Manjunatha ◽  
M Ramji
Keyword(s):  
Carbon Fibre ◽  
Cohesive Zone Model ◽  
Fibre Composite ◽  
Damage Model ◽  
Zone Model ◽  
Progressive Damage ◽  
Carbon Fibre Composite ◽  
Element Analysis ◽  
Damage Initiation ◽  
Progressive Damage Model

In this paper, the in-plane compression behaviour of open-hole carbon fibre composite specimens adhesively bonded with the external carbon fibre composite patches on the single- and double side are studied. Uniaxial compression tests are conducted on MTS machine using ASTM anti-buckling fixture. A 3D progressive damage model is developed to predict the damage initiation and failure in both unrepaired open cutout and repaired carbon fibre composite specimens under compressive load. Stress-based 3D-Hashin's failure criteria are used for predicting the fibre and matrix damage in carbon fibre composite. The cohesive zone model element is used for modelling the interlaminar delamination in carbon fibre composite specimen and also the adhesive layer between patch and specimen. Initial stiffness, damage initiation load and ultimate load of the specimen are obtained using progressive damage model based on finite element analysis, and they are compared against the experimental values. The load–deflection curve and the damage progression obtained from finite element analysis using progressive damage model is found to be in good coherence with the experimental predictions. In case of patch bonded carbon fibre composite specimens, failure mechanism starts with partial patch debonding followed by complete specimen failure.

Classification of Delamination and Matrix Cracking in Carbon Fibre Composite Plates Using Acoustic Emission (AE)

2009 ◽  
Author(s):  
Dirk Aljets ◽  
Alex Chong ◽  
Steve Wilcox ◽  
Karen Holford ◽  
Rhys Pullin ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Carbon Fibre ◽  
Composite Structures ◽  
Failure Modes ◽  
Fibre Composite ◽  
Composite Plates ◽  
Matrix Cracking ◽  
Actual Condition ◽  
Carbon Fibre Composite ◽  
Failure Types

Recent publications show that there is an increasing interest in the aircraft industry in monitoring the actual condition of a structure in real time and while the structure is in service. It is hoped that this Structural Health Monitoring (SHM) could make some regular inspections unnecessary and allow maintenance only when required. This is particularly important for CFRP structures for which aircraft manufacturers are increasingly interested. For these new composite structures where the experience of fatigue failure is relatively low, this technique could potentially be economical and improve the safety of the structures. Acoustic Emission is reported to be sensitive to the four failure types in composite materials, namely matrix cracking, delamination, debonding and fibre fracture. These failure modes can have different impacts on structural integrity and it is therefore of interest to identify these failure types before further maintenance steps are conducted. This report discusses different features in AE signals which can be used to identify the actual flaw type. These features were then applied to AE data collected from two different experiments on carbon fibre composite plates. These experiments were designed to induce the two different failure modes of matrix cracking and delamination. The data collected was used to train a neural network to recognise the two failure modes.

Fatigue damage development in a notched carbon fibre composite

1986 ◽  
Vol 5 (2) ◽  
pp. 143-157 ◽  
Author(s):  
S. Kellas ◽  
J. Morton ◽  
S.M. Bishop
Keyword(s):  
Carbon Fibre ◽  
Fatigue Damage ◽  
Fibre Composite ◽  
Damage Development ◽  
Carbon Fibre Composite

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.

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