Download or read book Long Term Isothermal Aging Effects on Carbon Fabric Reinforced PMR 15 Composites Compression Strength written by Kenneth J. Bowles and published by . This book was released on 1996 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Long Term Isothermal Aging Effects on Carbon Fabric Reinforced PMR 15 Composites written by KJ. Bowles and published by . This book was released on 1997 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Long Term Isothermal Aging Effects on Weight Loss Compression Properties and Dimensions of T650 35 Fabric Reinforced Pmr 15 Composites Data written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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

Download or read book Comparison of Graphite Fabric Reinforced PMR 15 and Avimid N Composites After Long Term Isothermal Aging at Various Temperatures written by and published by . This book was released on 1998 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Long Term Isothermal Aging Effects on Weight Loss Compression Properties and Dimensions of T650 35 Fabric Reinforced PMR 15 Composites Data written by and published by . This book was released on 2003 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recent Developments in Durability Analysis of Composite Systems written by H. Dardon and published by CRC Press. This book was released on 2022-01-26 with total page 493 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Progress in Durability Analysis of Composite Systems written by K.L. Reifsnider and published by CRC Press. This book was released on 1998-01-01 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Comparison of Graphite Fabric Reinforced Pmr 15 and Avimid N Composites After Long Term Isothermal Aging at Various Temperatures written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-10-25 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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

Download or read book Thermal and Mechanical Durability of Graphite Fiber Reinforced PMR 15 Composites written by and published by . This book was released on 1997 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nontraditional Methods of Sensing Stress Strain and Damage in Materials and Structures written by David A. Stubbs and published by ASTM International. This book was released on 1997 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: These facsimiles of 16 contributions from the symposium held in May 1996 in Orlando provide information on the behavior of materials and structures. The authors describe novel ways to measure point to point deformation (or strain, when normalized), procedures for measuring crack length and the stres

Download or read book High Temperature and Environmental Effects on Polymeric Composites written by Thomas S. Gates and published by ASTM International. This book was released on 1997 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Time Dependent and Nonlinear Effects in Polymers and Composites written by Richard Allan Schapery and published by ASTM International. This book was released on 2000 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation Improved reliability in commercial and military applications requires improved understanding of and predictive models for the time- dependent and nonlinear mechanical behavior of polymeric composites. The May 1998 American Society for Testing and Materials symposium sought to fuse the efforts in this direction of specialists in polymers and composites; these 18 papers are therefore grouped under the subheadings of polymers and composites. Primary polymer topics are chemical and physical aging, nonlinear viscoelasticity, and viscoplasticity. Composites' issues include: the effect of physical aging on time-dependent behavior, multiaxial nonlinear effects, compressive behavior, nonlinear viscoelasticity and viscoplasticity, failure mechanisms, hygrothermal effects, durability, and accelerated strength testing. Schapery is affiliated with the U. of Texas at Austin, and Sun is at Purdue U. Annotation copyrighted by Book News, Inc., Portland, OR.

Download or read book Thermo oxidative Stability of Graphite PMR 15 Composites written by Madhu S. Madhukar and published by . This book was released on 1994 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book COMPARISION OF GRAPHITE FABRIC REINFORCED PMR 15 AND AVIMID N COMPOSITES AFTER LONG TERM ISOTHERMAL AGING AT NASA TM 1998 107529 JUNE 1 1998 written by United States. National Aeronautics and Space Administration and published by . This book was released on 1999* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Revolutionary Materials written by Sampe and published by CRC Press. This book was released on 2000-11-06 with total page 1054 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of Advanced Materials written by and published by . This book was released on 2005 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mechanical Properties of Degraded PMR 15 Resin written by Luis Christophe Tsuji and published by . This book was released on 1998 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermo-oxidative aging produces a non-uniform degradation state in PMR-15 resin. A surface layer, usually attributed to oxidative degradation, forms. This surface layer has different properties from the inner material. A set of material tests was designed to separate the properties of the oxidized surface layer from the properties of interior material. Test specimens were aged at 316°C in either air or nitrogen, for durations of up to 800 hours. The thickness of the oxidized surface layer in air aged specimens, and the shrinkage and coefficient of thermal expansion (CTE) of nitrogen aged specimens were measured directly. The nitrogen-aged specimens were assumed to have the same properties as the interior material in the air-aged specimens. Four-point-bend tests were performed to determine modulus of both the oxidized surface layer and the interior material. Bimaterial strip specimens consisting of oxidized surface material and unoxidized interior material were constructed and used to determine surface layer shrinkage and CTE. Results confirm that the surface layer and core materials have substantially different properties.