A STUDY OF 954-2A/IM7 COMPOSITE LAMINATES CONTAINING A CENTRAL HOLE

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1461-1468
Author(s):  
HYUNGWON KIM
Keyword(s):  
Composite Laminates ◽  
Fiber Composites ◽  
Central Hole ◽  
Carbon Fiber Composites ◽  
Uniform Stress ◽  
Ray Method ◽  
X Ray ◽  
Width Direction ◽  
Uniform Stress Field ◽  
The Subject

Predicting microcracking properties of the composite laminates in nonuniform stress conditions was the subject in this paper. The uniform stress field meant the stresses were independent of the width direction. The material was the 954-2A/IM7 laminates containing a central hole. Microcracks initiated at the edge of the hole and propagated into the laminate. Because the tensile stress concentration decreased with distance, the microcracks were arrested before the edge of the laminate. Because carbon fiber composites were opaque, a x-ray method was used to detect the length of the propagating microcracks. The microcracking at the near edge of the hole could be reasonably predicted by considering the local laminate stresses and the microcracking toughness measured in unnotched laminates. However, the data away from the hole did not agree with the predictions. The local microcrack density was always much higher than that predicted by the local laminate stress.

X-ray-cured carbon–fiber composites for vehicle use

2009 ◽  
Vol 78 (7-8) ◽  
pp. 531-534 ◽  
Author(s):  
Arnold Herer ◽  
Richard A. Galloway ◽  
Marshall R. Cleland ◽  
Anthony J. Berejka ◽  
Daniel Montoney ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Fiber Composites ◽  
Carbon Fiber Composites ◽  
X Ray

X-Ray Curing of Carbon Fiber Composites for Structural Automotive Components

2017 ◽  
Author(s):  
Anthony Berejka ◽  
Dan Montoney ◽  
Dan Dispenza ◽  
Len Poveromo ◽  
Rick Galloway ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Fiber Composites ◽  
Carbon Fiber Composites ◽  
X Ray ◽  
Automotive Components

scholarly journals Mechanical and Impact Damage Analysis on Carbon/Natural Fibers Hybrid Composites: A Review

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 517 ◽  
Author(s):  
Carlo Santulli
Keyword(s):  
Composite Laminates ◽  
Natural Fiber ◽  
Hybrid Composites ◽  
Impact Damage ◽  
Natural Fibers ◽  
Fiber Composites ◽  
Carbon Fiber Composites ◽  
Impact Performance ◽  
Modes Of Failure ◽  
Post Impact

Hybrid composite laminates including carbon fibers and natural fibers, hence basalt and/or vegetable ones, draw on the experiences accumulated in studying the hybridization of fiberglass with carbon or natural fibers. Yet, in the case of carbon/natural fiber composites, the sense is different: in particular, the idea is to accept the reduction of properties from bare carbon fiber composites and the unavoidable complication in processing, induced by hybridization. The compensation obtained, which offers a rationale to this operation, is the improved toughness and a significant modification of the different modes of failure. This would bring a higher energy absorption and a substantially more effective damage tolerance. The aforementioned characteristics are particularly of interest in the case of flexural properties, impact properties, and residual post-impact performance.

Preparation of TiO2/CNT Composites and Effect of CNT's Structure on Morphology of Nano-TiO2

2013 ◽  
Vol 750-752 ◽  
pp. 259-264
Author(s):  
Feng Li ◽  
He Bian ◽  
Hui Zhang
Keyword(s):  
Heat Treatment ◽  
Carbon Fiber ◽  
Sol Gel ◽  
Fiber Composites ◽  
Carbon Fiber Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Morphology And Structure ◽  
Scanning Electron

Four kinds of TiO2/CNT (or carbon fiber) composites were successfully prepared by the sol-gel method using Ti(OBu)4 as precursor of TiO2, and untreated CNT, carboxylic CNT, hydroxylated CNT and carbon fiber were used as carriers, respectively. After heat treatment at 400 and 800°C, TiO2/CNT nanocomposites and purified TiO2 were obtained. Their structure and morphology were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results indicate that different carbon nanotubes and nanofiber have notable influences on the morphology and structure of TiO2 nanocrystals.

Monitoring of nylon 6,6/carbon fiber composites processing by X-ray diffraction and thermal analysis

2002 ◽  
Vol 86 (12) ◽  
pp. 3114-3119 ◽  
Author(s):  
Edson Cocchieri Botelho ◽  
Clara Leal Nogueira ◽  
Mirabel Cerqueira Rezende
Keyword(s):  
Thermal Analysis ◽  
Carbon Fiber ◽  
Fiber Composites ◽  
Carbon Fiber Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nylon 6,6 ◽  
Composites Processing

Technique of Measuring Low Percentages of Retained Austenite using Filtered X-Ray Radiation and an X-Ray Diffractometer*

1963 ◽  
Vol 7 ◽  
pp. 256-264 ◽  
Author(s):  
H. Robert Erard
Keyword(s):  
Retained Austenite ◽  
Counting Rate ◽  
Diffraction Line ◽  
Thermal Treatments ◽  
Volume Percent ◽  
Ray Method ◽  
Metallographic Examination ◽  
X Ray ◽  
Integrated Intensity ◽  
The Subject

AbstractThis paper describes a technique of measuring the volume percent retained austenite in steel using ordinary filtered X-radiation and an X-ray diffractometer. As compared with conventional rate-meter recordings or microphotometer traces of diffraction peaks, the subject technique extends the range of austenite determinations from the usual 7 % down to 1 %. It markedly improves over the entire range of measurement.Essentially, the technique consists of step scanning the profile of each selected martensite and austenite diffraction line and recording the corresponding intensity within a known probable error. The step-scanning, fixed-count, and counting-rate, recording operations are performed automatically by a counting-rate computer. The integrated intensity of each diffraction line is obtained by summation of intensity increments above background in accordance with the “trapezoidal rule.” For hardened steel, the best peak-to-background ratio is secured using filtered Cr Ka radiation with the vanadium filter located in the diffracted beam. The volume percent retained austenite is determined by direct comparison of the integrated intensity of an austenite line with the integrated intensity of a marten site line and from the relationships between intensity and concentration for the martensitic and austenitic phases.An application of the subject technique was its use in determining the retained austenite behavior of carburized 9310 steel. The volume percent austenite retained on the surfaces of as-quenched specimens was determined as a function of carburizing potential. The amount of retained austenite subsequently transformed by various combinations of tempering, refrigerating, and retempering treatments was successively ascertained. The amount of retained austenite determined using the subject technique compared closely with the amount of retained austenite measured by metallographic examination. However, the reproducibility of results was better for the X-ray method as compared to metallographie examination. The nondestructive nature of the X-ray method permitted successive measurements on the same surface following repeated thermal treatments.

scholarly journals Improved Performances of SiBCN Powders Modified Phenolic Resins-Carbon Fiber Composites

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 955
Author(s):  
Wenjie Yuan ◽  
Yang Wang ◽  
Zhenhua Luo ◽  
Fenghua Chen ◽  
Hao Li ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Photoelectron Spectroscopy ◽  
Phenolic Resin ◽  
Pyrolysis Product ◽  
Ablation Rate ◽  
Fiber Composites ◽  
Carbon Fiber Composites ◽  
Phenolic Resins ◽  
X Ray ◽  
Ablation Resistance

The effect of SiBCN powder on properties of phenolic resins and composites was analyzed. Compared with phenolic resins, the thermal stability of SiBCN powder modified phenolic resins (the SiBCN phenolic resins) by characterization of thermogravimetric analysis (TGA) improved clearly. It was found by X-ray photoelectron spectroscopy (XPS) that reactions between SiBCN powder and the pyrolysis product of phenolic resins were the main factor of the increased residual weight. TGA and static ablation of a muffle furnace were used to illustrate the roles of SiBCN powder on increasing oxidation resistance of SiBCN powder-modified phenolic resin–carbon fiber composites (SiBCN–phenolic/C composites), and the oxidative product was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). For SiBCN–phenolic/C composites, the occurrence of oxidation reaction and the formation of protective crust contributed to improving oxidative resistance. The result of the oxygen-acetylene test showed that the linear ablation rate (LAR) and mass ablation rate (MAR) of phenolic resin–carbon fiber composites reduced from 0.052 ± 0.005 mm/s to 0.038 ± 0.004 mm/s and from 0.050 ± 0.004 g/s to 0.043 ± 0.001 g/s by introducing SiBCN powder, respectively. The mechanism of ablation resistance after the introduction of SiBCN powder was investigated. The high melt-viscosity of SiBCN powder caused SiBCN powder to remain on the surface of composites and protect the internal resins and carbon fibers. The oxidation of SiBCN powder and volatilization of oxide can consume energy and oxygen, thus the ablation resistance of SiBCN–Ph composite was improved.

scholarly journals Mechanical Properties of Epoxy and Its Carbon Fiber Composites Modified by Nanoparticles

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Fang Liu ◽  
Shiqiang Deng ◽  
Jianing Zhang
Keyword(s):  
Carbon Fiber ◽  
Composite Laminates ◽  
Fiber Composite ◽  
Fiber Composites ◽  
Epoxy Composites ◽  
Compressive Property ◽  
Carbon Fiber Composites ◽  
Carbon Fiber Composite ◽  
Compressive Performance ◽  
Carbon Fiber Epoxy

Compressive properties are commonly weak parts in structural application of fiber composites. Matrix modification may provide an effective way to improve compressive performance of the composites. In this work, the compressive property of epoxies (usually as matrices of fiber composites) modified by different types of nanoparticles was firstly investigated for the following study on the compressive property of carbon fiber reinforced epoxy composites. Carbon fiber/epoxy composites were fabricated by vacuum assisted resin infusion molding (VARIM) technique using stitched unidirectional carbon fabrics, with the matrices modified with nanosilica, halloysite, and liquid rubber. Testing results showed that the effect of different particle contents on the compressive property of fiber/epoxy composites was more obvious than that in epoxies. Both the compressive and flexural results showed that rigid nanoparticles (nanosilica and halloysite) have evident strengthening effects on the compression and flexural responses of the carbon fiber composite laminates fabricated from fabrics.

scholarly journals Exhaust system piping made by hydroforming: relations between stresses, microstructure, mechanical properties and surface

2020 ◽  
Vol 20 (4) ◽  
Author(s):  
Barbara Kucharska ◽  
Oskar Moraczyński
Keyword(s):  
Complex Shape ◽  
Surface Condition ◽  
Exhaust System ◽  
Nickel Steel ◽  
Ray Method ◽  
Pipe Wall Thickness ◽  
X Ray ◽  
Car Exhaust ◽  
The Subject ◽  
304L Steel

Abstract The subject of research is car exhaust system piping made of chromium–nickel steel of grade AISI304L with a unique, complex shape that was obtained by hydroforming technology. The purpose of the research was to determine the relation between the microstructure features, surface condition, hardness and the stresses on the external surface as determined by the sin2ψ X-ray method. We found that the stresses were tensile and correlated with the steel hardness, i.e. they were greater where the hardness was higher. Moreover, longitudinal stresses showed a relationship with pipe wall thickness, while circumferential stresses did so only partially. According to our data, the greatest value of stress determined in the pipe amounted to 290 MPa, and was close to the yield point of the strain hardened 304L steel. As depicted via XRD and SEM examination, the pipe stress level and hardness were influenced by the transition γ→α’. Furthermore, in the region of higher stress and hardness, the amount of martensite was 10 vol.%. We also noted that the pipe’s outer surface when subjected to friction against the die shows lesser roughness compared to its inner surface upon exposure to water under pressure.

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