Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 10

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Author: United States. National Aeronautics and Space Administration
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
ISBN: 9781729196731
Category : Science
Languages : en
Pages : 30

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Book Description
Extensive effort is currently being expended to demonstrate the feasibility of using high-performance, polymer-matrix composites as engine structural materials over the expected operating lifetime of the aircraft, which can extend from 18,000 to 30,000 hr. The goal is to develop light-weight, high-strength, and high-modulus materials for use in higher temperature sections of advanced 21 st century aircraft propulsion systems. To accomplish this goal, it is necessary to pursue the development of thermal and mechanical durability models for graphite-fiber-reinforced, polymer-matrix composites. Numerous investigations have been reported regarding the thermo-oxidative stability (TOS) of the polyimide PMR-15 (1-5). A significant amount of this work has been directed at edge and geometry effects, reinforcement fiber influences, and empirical modeling of high-temperature weight loss behavior. It is yet to be determined if the information obtained from the PMR-15 composite tests is applicable to other polyimide-matrix composites. The condensation-curing polymer Avimid N is another advanced composite material often considered for structural applications at high temperatures. Avimid N has better thermo-oxidative stability than PMR-15 (6), but the latter is more easily processed. The most comprehensive study of the thermo-oxidative stability of Avimid N neat resin and composites at 371 (infinity)C is found in Salin and Seferis (7). The purposes of the work described herein were to compare the thermal aging behavior of these two matrix polymers and to determine the reasons for and the consequences of the difference in thermal durability. These results might be of some use in improving future polymer development through the incorporation of the desirable characteristics of both polyimides. Bowles, Kenneth J. and McCorkle, Linda and Ingrahm, Linda Glenn Research Center NAS3-27351; RTOP 538-06-15

Author: K.L. Reifsnider
Publisher: CRC Press
ISBN: 9789054109600
Category : Technology & Engineering
Languages : en
Pages : 380

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Book Description
Composite material systems are the basis for much of the natural world around us and are rapidly becoming the basis for many modern engineering components. A controlling feature for the general use of such systems is their damage tolerance, durability and reliability. The present book is a comprehensive cross section of the state of the art in the field of the durability of polymer-based, composite, and adhesive systems. As such, it is of special value to researchers concerned with the frontier of the field, to students concerned with the substance of the subject, and to the applied community concerned with the finding methodologies that make it possible to design safe and durable engineering components using material systems.

Author: KJ. Bowles
Publisher:
ISBN:
Category : Carbon fiber
Languages : en
Pages : 6

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Book Description
Earlier work that reported relationships between compression properties and elevated-temperature aging duration and weight losses also pointed out the apparent influence of surface layer formation and growth on the retention of compression properties during extended aging times. Since that time, further studies have focused on evaluating the growth of the surface layer. The composition and features of this layer were found to change as the aging temperature changed. Microcracks and small voids initiated and advanced inward at all temperatures. Visible oxidation at the surface occurred only at temperatures above 260°C. Relationships between layer thickness, aging time, and temperature were evaluated and empirically formulated. Then, the compression properties were graphically related to the surface layer thickness with excellent correlation.

Author: H. Dardon
Publisher: CRC Press
ISBN: 9789058091031
Category : Technology & Engineering
Languages : en
Pages : 500

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Book Description
The papers from these proceedings address experimental and analytical methods for the characterization and analysis of modern composite and adhesive systems. They have been produced to provide understanding that can be used to design safe, reliable engineering components.

Author: M. P. Hanson
Publisher:
ISBN:
Category : Composite materials
Languages : en
Pages : 20

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Book Description
Composites were exposed in circulating and static air environments up to 589 K for a maximum of 1000 hours. Composites of HT-S, HM-S, Thornel 50S, and Fortafil 5-Y fiber and a new addition type polyimide resin were laminated in a matched-die mold. Flexural strengths, flexural modulus, and interlaminar shear strengths were determined at 297, 533, and 598 K after various durations of exposure. Composite and fiber weight loss characteristics were determined by isothermal gravimetric analysis in air. Properties of composites exposed and tested at the environment temperatures were compared with those determined under short-term exposure. A new short beam interlaminar shear fixture is described. Environmental effects of long-term ambient temperature exposure on the elevated temperature mechanical properties of graphite/polyimide composites are presented.

Author: Young Kwon
Publisher: Springer Science & Business Media
ISBN: 0387363181
Category : Technology & Engineering
Languages : en
Pages : 634

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Book Description
This book presents the state-of-the-art in multiscale modeling and simulation techniques for composite materials and structures. It focuses on the structural and functional properties of engineering composites and the sustainable high performance of components and structures. The multiscale techniques can be also applied to nanocomposites which are important application areas in nanotechnology. There are few books available on this topic.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 34

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Author: Sampe
Publisher: CRC Press
ISBN: 9781587160622
Category : Technology & Engineering
Languages : en
Pages : 1054

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Book Description