scholarly journals Thermal and Principal Ablation Properties of Carbon-Fibre-Reinforced Polymers with Out-of-Plane Fibre Orientation

2021 ◽  
Vol 7 (3) ◽  
pp. 64
Author(s):  
Sebastian Eibl ◽  
Thomas J. Schuster
Keyword(s):  
Carbon Fibre ◽  
Thermal Loading ◽  
Mechanical Performance ◽  
Fibre Orientation ◽  
Matrix Degradation ◽  
Initial State ◽  
Out Of Plane ◽  
Carbon Fibre Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymers ◽  
Fibre Angle

This work characterises thermal properties of a typical epoxy-based carbon-fibre-reinforced polymer used in aircraft construction, but with an out-of-plane fibre orientation, and assesses its potential as a structural ablative material. Samples of the commercially available Hexply® 8552/IM7 are prepared with out-of-plane angles up to 90°, with a focus on 0° to 15°, enhancing thermal conductivity through the thickness of the panel. Ablation processes are simulated by a hot-air blower at 580 °C, and examined in detail by ultrasonic testing and microfocused computed X-ray tomography afterwards. Matrix degradation is characterised by infrared spectroscopy and mass loss. To assess structural properties, tensile, compression, and bending tests are performed. The results show a loss in mechanical performance with an increasing fibre angle, which may be negligible for angles lower than ~5° in the initial state. Composite material with an out-of-plane fibre orientation is deeply penetrated concerning matrix degradation by thermal loading, but it is held together by the fibres fixed in the intact matrix underneath. This type of material shows a high potential for structural components in single-use, high-temperature, ablative applications with a focus on saving weight.

scholarly journals Predicting Delaminations and Residual Strength of Carbon Fibre Reinforced Polymers (CFRP) After One-Sided Thermal Loading by Means of Infrared Spectroscopy

2021 ◽  
Author(s):  
Tanja Marina Vetter ◽  
Sebastian Eibl ◽  
Hans-Joachim Gudladt
Keyword(s):  
Infrared Spectroscopy ◽  
Ir Spectroscopy ◽  
Carbon Fibre ◽  
Residual Strength ◽  
Thermal Loading ◽  
Incline Plane ◽  
Matrix Degradation ◽  
Reinforced Polymers ◽  
Linear Discriminant ◽  
Carbon Fibre Reinforced Polymers

AbstractThis study investigates the change of chemical, structural, and mechanical properties of carbon fibre reinforced polymers (CFRP) after one-sided thermal loading. Therefore, CFRP samples (HexPly® 8552/IM7) with varying thickness (4 and 8 mm) are irradiated at different heat fluxes (15, 30, and 50 kW/m2). For a depth-resolved view on matrix degradation inside the CFRP, infrared spectroscopy (ATR-FTIR) is applied along a ground incline plane. A change of structural properties in the form of developing delaminations is investigated with microfocused computed X-ray tomography (µCT). The loss of residual strength is determined by means of interlaminar shear strength testing (ILSS). The evaluation of the data shows that delaminations occur predominantly dependent on temperature and only beyond a certain level of matrix degradation traceable by IR spectroscopy. It is also shown that delaminations are mainly responsible for the loss of strength. Furthermore, linear discriminant analysis (LDA) is performed to predict the presence of delaminations. This information provides a basis for a reliable prediction of the residual strength by IR spectroscopy after one-sided thermal loading.

scholarly journals Synergetic effects of carbon nanotube-graphene nanoplatelet hybrids in carbon fibre reinforced polymer composites

2018 ◽  
Vol 188 ◽  
pp. 01015 ◽  
Author(s):  
Magda Silva ◽  
Diogo Vale ◽  
Jéssica Rocha ◽  
Nuno Rocha ◽  
Raquel Miriam Santos
Keyword(s):  
Carbon Fibre ◽  
Mechanical Performance ◽  
Synergistic Effects ◽  
Three Dimensional ◽  
Hybrid Filler ◽  
Synergetic Effects ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
3D Architecture ◽  
Fibre Reinforced Polymer

Hybrid filler systems of carbon-based nanoparticles with different geometry shapes, one-dimensional (1D-) carbon nanotubes (CNTs) and two-dimensional (2D-) graphene nanoplatelets (GnPs), were dispersed into epoxy matrix, using an intensive mixer, to evaluate their promising synergistic effects. In this work, the influence of different CNT/GnP ratios on the dispersion level, electrical and mechanical performance of epoxy-based nanocomposites was investigated. It was found that the size and number of GnP agglomerates are significantly reduced with the incorporation of CNTs, due to the formation of a co-supporting three-dimensional (3D-) architecture that delays re-agglomeration of the nanoplatelets. The combination of CNTs and GnPs, at an overall concentration of 0.043 wt. %, synergistically increase the mechanical performance and reduce the electrical percolation threshold of nanocomposites comparatively to the single filled systems. The transversal tensile properties, including elastic modulus – E2 and failure strength – Yt, of carbon fibre reinforced polymer (CFRP) composites were studied and synergetic effects were also found when combining CNTs with GnPs.

Blanking of Unidirectional Carbon Fibre Reinforced Plastics

2015 ◽  
Vol 794 ◽  
pp. 223-230 ◽  
Author(s):  
Anton Shirobokov ◽  
Sophie Kerchnawe ◽  
Michael Terhorst ◽  
Patrick Mattfeld ◽  
Fritz Klocke
Keyword(s):  
Carbon Fibre ◽  
Cutting Force ◽  
Mechanical Performance ◽  
Fibre Orientation ◽  
Minimum Weight ◽  
Parallel Fibre ◽  
Reinforced Plastics ◽  
Thermoset Resin ◽  
Cutting Line ◽  
Water Jet Cutting

Fibre reinforced plastics (FRP) are being increasingly used for advanced applications where an appropriate mechanical performance should be achieved at minimum weight. A substantial increase of the FRP usage is expected across various industries e.g. in automotive sector in the nearest future. This leads to the mass manufacturing of FRP components. Reduction of manufacturing costs of FRP components is regarded as the main enabler for the usage of this material in mass production. Although FRP components are manufactured near-net-shape, they often have to be pierced or trimmed in one of the last manufacturing steps. With rising production numbers blanking is a potentially more cost efficient technology for trimming and piercing of FRP components compared to the conventionally performed abrasive water jet cutting or machining. The mechanisms of FRP separation in blanking have not yet been researched. In particular, the influence of the fibre orientation relative to the cutting line on the cutting force is not known. In the scope of this work an experimental study of blanking of a unidirectional carbon fibre reinforced plastic with a thermoset resin at different fibre orientations to the cutting line was performed. It was shown that the cutting force decreases from the perpendicular to the parallel fibre orientation to the cutting line. A possible mechanical explanation of this dependency was formulated.

scholarly journals Development of Laser Drilling Strategy for Thick Carbon Fibre Reinforced Polymer Composites (CFRP)

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2674
Author(s):  
Sharizal Ahmad Sobri ◽  
Robert Heinemann ◽  
David Whitehead
Keyword(s):  
Carbon Fibre ◽  
High Strength ◽  
Fibre Laser ◽  
Machining Parameters ◽  
Performance Measurements ◽  
Reinforced Polymers ◽  
Carbon Fibre Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymers ◽  
Fibre Reinforced Polymer ◽  
Experimental Findings

Composites from carbon fibre reinforced polymers (CFRPs) play a significant role in modern manufacturing. They are typically used in aerospace and other industries that require high strength-to-weight ratios. Composite machining, however, remains a challenging job and sometimes is hampered by poor efficiency. Despite considerable research being conducted over the past few years on the machining of composite materials, the material nevertheless suffers from delamination, fibre loss, and imperfect finishing of the fuselage. Laser technology is becoming increasingly popular as an alternative approach to cutting and drilling composites. Experiments have been conducted with a CFRP thickness of 25.4 mm using fibre laser to test the effect of the machining parameters on the primary performance measurements. In this study, different machining criteria are used to assess the fibre laser ability of thick CFRP composites for drilling operation. The experimental findings revealed that a fibre laser is capable of penetrating a thick CFRP to a depth of 22 mm by using a novel drilling procedure.

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