Four families of carbon fiber reinforced composites (CFRC) used in aeronautical industry were evaluated by flexural and interlaminar shear tests. It is also characterized three families of non-conditioned and conditioned CFRC by compression test. The composites were obtained by hand lay-up process in autoclave by using prepregs based on epoxy matrices (F155 and F584) and carbon fiber fabric reinforcements (PW-"Plain Weave" and 8HS-"Eight Harness Satin"). The F155-epoxy matrix was cured at 121 °C and the F584-epoxy type at 177 °C. After molding, the laminates were cut in specimens attending the ASTM D790 for the flexural test, the ASTM D2344 for the interlaminar shear test (ILSS) and the ASTM D3410 for the compressive test. The compressive tests were performed for testing the specimens before and after hygrothermal conditioning. The results show that the F584-epoxy matrix laminates present higher mechanical properties when compared to the F155-epoxy ones. The shear-tested samples observed by scanning electron microscopy and that ones tested in flexural, analyzed by stereoscopy, revealed that the fractured surfaces present typical aspects. The compressive results show that the hygrothermal conditioning caused the decrease of the compressive strength in, approximately, 8-20% depending on the laminate type. The failure modes of the tested specimens were evaluated showing good agreement with the literature.
This paper compares interlaminar shear strength, interlaminar fracture toughness and compression-after-impact strength of epoxy resin matrix composites reinforced with carbon fiber woven fabrics and carbon fiber felts, and investigates the influences of weave pattern and needle-punching density. With regard to the weave pattern of fabric layers in woven laminates and felt/resin composites, plain weave with a smaller radius of curvature of yarns is preferable for obtaining higher damage tolerance...
#1Alan Baker(DST: Defence Science and Technology Organisation)H-Index: 23
#2Paul J. Callus(DST: Defence Science and Technology Organisation)H-Index: 11
Last. K.H. Leong(CRCs: Cooperative Research Centre)H-Index: 11
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This paper describes an affordable approach to substitute metallic honeycomb panels with more durable stiffened graphite/epoxy composite panels. Although the technology is generic, it is being demonstrated on a honeycomb panel for the Royal Australian Air Force (RAAF) F-111 aircraft. This panel was selected with the aim of validating the design, manufacture and certification approaches. Future work will focus on airworthiness certification, operational testing, addressing service related issues,...
The objective of this work is to analyze the mechanism of interaction between AS4 carbon fiber and a phenolic epoxy matrix in composites cured by electron beam and to improve the interlaminar shear strength (ILSS) of the composites by modifying the carbon fiber. Some promising results have been achieved by electrochemical treatment of the carbon fibers and subsequent coating with an electron-beam-compatible coupling agent. The ILSS of an electron-beam-cured composite was improved from 72.1 to 81...
#1Shang-Lin Gao(HKUST: Hong Kong University of Science and Technology)H-Index: 33
#2Jang Kyo Kim(HKUST: Hong Kong University of Science and Technology)H-Index: 100
The effect of cooling rate on impact damage performance of carbon fibre/polyether ether ketone (PEEK) matrix composite is characterised based on the instrumented drop-weight impact test, scanning acoustic microscopy (SAM) damage evaluation and compression-after-impact (CAI) test. Judging from the incipient impact load, incipient impact energy and total damage area, the ability to resist damage initiation upon impact was higher in the order of fast-cooled carbon/PEEK, slow-cooled carbon/PEEK and ...
Abstract In this study, various hygroscopic effects of such parameters as hygrothermal temperature, matrix volume ratio ( V m ), void volume ratio ( V v ), specimen thickness, lay-up sequence and internal stress were investigated for epoxy/carbon fiber composite laminates. The specimen thickness and lay-up sequence had little effect on the through-the-thickness water absorption behavior of composite laminates, but the other parameters affected the moisture absorption rate and equilibrium water u...
#1Russell J. Varley(CSIRO: Commonwealth Scientific and Industrial Research Organisation)H-Index: 34
#2Jonathon Hodgkin(CSIRO: Commonwealth Scientific and Industrial Research Organisation)H-Index: 1
Last. George P. Simon(Monash University, Clayton campus)H-Index: 78
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This paper examines the effect of the addition of PSF upon the final properties and network structure of the TGAP/DDS system after cure and post-cure. It also compares the differences in the network structure and properties of the modified system between samples in which the epoxy resin and thermoplastic had been prereacted and those which had been simply mixed together. The thermal properties of the network structure were investigated using dynamic mechanical thermal analysis while the chemical...
Abstract The effect of a thermoplastic polyester binder on the thermophysical and mechanical properties of an S2-glass/epoxy–amine system was investigated. The purpose of the polymeric binder is to bond the individual fabric layers together during preforming prior to composite fabrication. This paper will address the significance of the binder chemistry, i.e., the compatibility of the binder with the matrix polymer, on the composite properties. The peel strength of preforms consolidated with var...
Last. Anthony M. Waas(UM: University of Michigan)H-Index: 58
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Abstract An analytical and experimental study of the compressive behavior of unidirectional glass/epoxy composites loaded in the fiber direction has been carried out for a range of fiber volume fractions. It was observed experimentally that glass/epoxy composites failed predominantly by splitting at lower fiber volume fractions ( V f ) and by a combination of splitting and kinking at higher V f . In contrast, carbon/epoxy composites were found to fail by kinking only. A mechanical model develope...
Carbon and glass fabric epoxy prepreg with a highly accelerated curing system were compared and used to build a Boeing 737 flap hinge fairing production part. The prepreg materials, uncured and cured, were analyzed to determine physical and mechanical properties. Initial evaluations of the carbon prepreg indicated unique and desirable characteristics including dual temperature cure and excellent handling characteristics. Therefore, this material was selected for the use in the development of a p...
The effect of fibrous reinforcement and solvent content on moisture uptake in composite laminate was investigated. Two materials using identical epoxy resin systems but different reinforcements—glass vs. carbon fibers—and of different solvent content—low vs. normal— were examined. Samples were characterized in terms of water absorption and desorption. Mechanical and thermal properties including flexural modulus, flexural strength, and glass transition temperature were measured. Results clearly s...
In this work, the effect of inclusion of 0.5 to 2 wt% multiwalled carbon nanotubes (MWCNT) in epoxy on the performance of the epoxy-carbon fabric (CF) composites is analyzed. High-resolution transmission electron microscopy (HRTEM) correlated the dispersion of the nanofillers and morphology of the nanocomposites. The tensile and fracture properties of the composites improved significantly with MWCNT content. Beyond 1 wt%, the properties declined in both nano- and multiscale composites due to the...
In this work, we examine the relationships between the microstructure and the mechanical properties of glass fiber–reinforced polyamide 6,6 composite materials (Vf = 54%). These materials made by t...
This work focuses on investigating the curing process of an epoxy-based resin—Aerotuf 275-34TM, designed for aerospace applications. To study the curing degree of Aerotuf 275-34TM under processing conditions, woven carbon fiber fabric (WCFF)/Aerotuf 275-34TM composite laminates were produced by compression molding using different processing temperatures (110, 135, 160, and 200 °C) during 15 and 30 min. Then, the mechanical behavior of the composite laminates was evaluated by tensile tests and co...
Radar absorbing structures (RAS) based on frequency selective surface (FSS) can be prepared to meet tailored properties in reducing electromagnetic interference in the microwave range, in addition to presenting mechanical properties suitable for structural applications. This article presents a study involving RAS processed by appropriate lamination and molding of glass fiber/epoxy resin prepreg and nonwoven of carbon fiber recovered with nickel and containing patterned unit cells to evaluate the...
This work presents an experimental and numerical investigation of the effects of pre-existing core damage on aluminum honeycomb core composite sandwich structures. Quasi static flexural and compres...
Last. T. S. Roopa(RVCE: R.V. College of Engineering)H-Index: 1
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Abstract This paper presents the effect of process parameters of twin screw extruder and addition of Cloisite-15A on mechanical, thermal and moisture barrier properties of epoxy/Cloisite-15A nanoco...
Abstract A composite single-lap bolted joint was experimentally studied and its bearing behavior was predicted numerically. Prior to performing the experiment, an appropriate e/D ratio of the composite material was determined via double-lap bolted joint tests. Using the obtained e/D ratio, specimens were manufactured, and single-lap composite bolted joint tests were subsequently performed. Various joint tests were conducted with the number of bolt holes, pre-torque, and thickness as experimental...
#1Yunqi Wang(UNNC: The University of Nottingham Ningbo China)H-Index: 3
#2Xiaoling Liu(UNNC: The University of Nottingham Ningbo China)H-Index: 11
Last. Nusrat Sharmin(UNNC: The University of Nottingham Ningbo China)H-Index: 18
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Abstract This work presents manufacturing, processing and characterisation of the phosphate glass fibre (PGF) products for biomedical applications, including multifilament PGF strands, yarns and textiles, and PGF textile composites. The multifilament production of PGF strands was achieved using a 50-nozzle bushing. PGF yarns, with a linear density of 87 tex, a twist angle of 14° and a tensile strength of 0.29 N/tex, were produced by combining 8 fibre strands using the ring-spinning method. PGF t...
The use of composite materials in the most varied industrial sectors has increased considerably in recent years, especially those made of carbon fiber/epoxy resin. For this reason, the use of these materials need a better understanding of their mechanical behavior, especially when submitted to cyclical load requests, especially about compression, which is the object of study of this work. Residual strength degradation in CFRP is evaluated by numerical models and experimental tests relating the r...