Author: Kenneth J. Bowles Publisher: ISBN: Category : Languages : en Pages : 20
Book Description
A study was conducted to determine the effects of long-term isothermal thermo-oxidative aging on the compressive properties of T-650-35 fabric reinforced PMR-15 composites. The temperatures that were studied were 204, 260, 288, 316, and 343 C. Specimens of different geometries were evaluated. Cut edge-to-surface ratios of 0.03 to 0.89 were fabricated and aged. Aging times extended to a period in excess of 15,000 hours for the lower temperature runs. The unaged and aged specimens were tested in compression in accordance with ASTM D-695. Both thin and thick (plasma) specimens were tested. Three specimens were tested at each time/temperature/geometry condition. The failure modes appeared to be initiated by fiber kinking with longitudinal, interlaminar splitting. In general, it appears that the thermo-oxidative degradation of the compression strength of the composite material may occur by both thermal (time-dependent) and oxidative (weight-loss) mechanisms. Both mechanisms appear to be specimen-thickness dependent.
Author: KJ. Bowles Publisher: ISBN: Category : Carbon fiber Languages : en Pages : 16
Book Description
A study was conducted to determine the effects of long-term isothermal thermo-oxidative aging on the compressive properties of T-650-35 fabric reinforced PMR-15 composites. The temperatures that were studied were 204, 260, 288, 316, and 343°C. Specimens of different geometries were evaluated. Cut edge-to-surface ratios of 0.03 to 0.89 were fabricated and aged. Aging times extended to a period in excess of 15 000 h for the lower temperature runs.
Author: National Aeronautics and Space Administration (NASA) Publisher: Createspace Independent Publishing Platform ISBN: 9781720615163 Category : Languages : en Pages : 64
Book Description
A cooperative program was conducted with the General Electric Aircraft Engines plant in Evendale, Ohio, to study the effects of long-term isothermal aging at elevated temperatures on compression and thermal durability properties of T650 35 fabric-reinforced PMR 15 composites. This degradation study was conducted over an approximate time period of 3 1/2 yr. The aging temperatures were 204, 260, 288, 316, and 343 C. Specimens of different dimensions were evaluated. Specimens with ratios of the cut edge to total surface area of 0.03 to 0.89 were fabricated and aged. The aged and unaged specimens were tested in compression as specified in Test Method for Compressive Properties of Rigid Plastics (ASTM D695M). Thickness changes, degraded surface layer growth, weight loss, and failure modes were monitored and recorded. All property changes were thickness dependent.Bowles, Kenneth J. and Tsuji, Luis and Kamvouris, John and Roberts, Gary D.Glenn Research CenterAGING (MATERIALS); ISOTHERMAL PROCESSES; FABRICATION; MECHANICAL PROPERTIES; POLYIMIDES; STRUCTURAL WEIGHT; COMPRESSIBILITY; COMPOSITE MATERIALS; FAILURE MODES; DURABILITY; PLASTICS; THICKNESS; DEGRADATION; SURFACE LAYERS; HIGH TEMPERATURE
Author: National Aeronautics and Space Administration (NASA) Publisher: Createspace Independent Publishing Platform ISBN: 9781722108601 Category : Languages : en Pages : 30
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: Kishore V. Pochiraju Publisher: Springer Science & Business Media ISBN: 1441993088 Category : Technology & Engineering Languages : en Pages : 681
Book Description
Long-Term Durability of Polymeric Matrix Composites presents a comprehensive knowledge-set of matrix, fiber and interphase behavior under long-term aging conditions, theoretical modeling and experimental methods. This book covers long-term constituent behavior, predictive methodologies, experimental validation and design practice. Readers will also find a discussion of various applications, including aging air craft structures, aging civil infrastructure, in addition to engines and high temperature applications.
Author: H. Dardon Publisher: CRC Press ISBN: 1000443728 Category : Technology & Engineering Languages : en Pages : 493
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: Kenneth J. Bowles
Author: KJ. Bowles
Author: National Aeronautics and Space Administration (NASA)
Author: 
Author: 
Author: National Aeronautics and Space Administration (NASA)
Author: Kishore V. Pochiraju
Author: Madhu S. Madhukar
Author: United States. National Aeronautics and Space Administration
Author: H. Dardon