Download or read book Mechanical Properties of Degraded Pmr 15 Resin 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 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermo-oxidative aging produces a nonuniform 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 hr. 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.Tsuji, Luis C.Glenn Research CenterDEGRADATION; MECHANICAL PROPERTIES; POLYIMIDE RESINS; SURFACE LAYERS; MODULUS OF ELASTICITY; THERMAL EXPANSION; COEFFICIENTS; BEND TESTS

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.

Download or read book Mechanical Properties of Degraded PMR 15 Resin written by LC. Tsuji and published by . This book was released on 2000 with total page 15 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 h. 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. 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.

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 23 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. 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. KEYWORDS: testing, aging, degradation, polymer matrix, material properties, test methods.

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 13 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. 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. KEYWORDS: testing, aging, degradation, polymer matrix, material properties, test methods.

Download or read book Mechanical Properties Of Degraded PMR 15 Resin NASA TM 1998 208487 Dec 3 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 Mechanisms of Chemical Degradation in PMR 15 Composites written by Ronan Anthony Cunningham and published by . This book was released on 1997 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction: The observed behavior of PMR-15 resin plaques exposed to high-temperature air for long periods of time includes mass loss, the formation of a surface layer of visibly altered material (Fig. 1), the formation of cracks in this layer, and loss of measured mechanical properties (refs. 1 and 2). Composites made with this resin also show these behaviors, and also transverse microcracking (ref. 3). These behaviors are detrimental to the durability of composite parts. It is clear that these behaviors have complex origins. Mechanisms at work include diffusion of the environment into the material, chemical reactions, changes in resin properties, resin shrinkage, changes in composite properties, changes in the stress state, and cracking. These mechanisms are interdependent, such that is very difficult to isolate the effect of any one mechanism on the behavior of a typical test specimen (Fig. 2). The objectives of this work are: (1) to understand the observed degradation phenomena in terms of mechanisms that are simple enough that they can be modeled, and (2) to use this understanding to design and execute a test program that will isolate the effects of the individual mechanisms and allow the collection of quantitative information about them.

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 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 Ageing of Composites written by Rod Martin and published by Elsevier. This book was released on 2008-08-29 with total page 543 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ageing of composites is a highly topical subject given the increasing use of composites in structural applications in many industries. Ageing of composites addresses many of the uncertainties about the long-term performance of composites and how they age under conditions encountered in service.The first part of the book reviews processes and modelling of composite ageing including physical and chemical ageing of polymeric composites, ageing of glass-ceramic matrix composites, chemical ageing mechanisms, stress corrosion cracking, thermo-oxidative ageing, spectroscopy of ageing composites, modelling physical and accelerated ageing and ageing of silicon carbide composites. Part two examines ageing of composites in transport applications including aircraft, vehicles and ships. Part three reviews ageing of composites in non-transport applications such as implants in medical devices, oil and gas refining, construction, chemical processing and underwater applications.With its distinguished editor and international team of contributors, Ageing of composites is a valuable reference guide for composite manufacturers and developers. It also serves as a source of information for material scientists, designers and engineers in industries that use composites, including transport, chemical processing and medical engineering. - Addresses many of the uncertainties about the long-term performance of composites and how they age under conditions encountered in service - Reviews processes and modelling of composite ageing including chemical ageing mechanisms and stress corrosion cracking - Discusses ageing of composites in both transport and non-transport applications ranging from aircraft to implants in medical devices

Download or read book Time Dependent Constitutive Behavior and Fracture Failure Processes Volume 3 written by Tom Proulx and published by Springer Science & Business Media. This book was released on 2011-05-10 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: This the third volume of six from the Annual Conference of the Society for Experimental Mechanics, 2010, brings together 56 chapters on Time-Dependent Constitutive Fracture and Failure. It presents early findings from experimental and computational investigations on Time Dependent Materials including contributions on Thermal and Mechanical Characterization, Coupled Experimental and Computational Analysis of Fracture Path Selection, Procedures for Mixed Mode Fracture Testing of Bonded Beams, and Experimental Study of Voids in High Strength Aluminum Alloys.

Download or read book Longtime Durability of PMR 15 Matrix Polymer at 204 260 288 and 316 C written by and published by . This book was released on 2001 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Longtime Durability of Pmr 15 Matrix Polymer at 204 260 288 and 316 C written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-16 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Isothermal weight loss studies at the Glenn (Lewis) Research Center were conducted at four temperatures (204, 260, 288, and 316 C) with specimens of varied geometric shapes to investigate the mechanisms involved in the thermal degradation of PMR-15. Both neat resin behavior and composite behaviors were studied. Two points of interest in these studies are the role(s) of oxygen in the mechanisms involved in the thermo-oxidative degradation of these composite materials and the dimensional changes that occur during their useable lifetime. Specimen dimensional changes and surface layer growth were measured and recorded. It was shown that physical and chemical changes take place as a function of time and location in PMR-15 neat resin and composites as aging takes place in air at elevated temperatures. These changes initiate at the outer surfaces of both materials and progress inward following the oxygen as it proceeds by diffusion into the central core of each material. Microstructural changes cause changes in density, material shrinkage (strains), glass transition temperature, dimension, dynamic shear modulus, and compression properties. These changes also occur slowly dividing the polymer material into two distinct parts: a visibly undamaged core section between two visibly damaged surface layers. The surface layer has a significant effect on compression properties of thinner specimens, but the visibly undamaged core material controls these properties for specimens having eight or more plies. It was demonstrated that there are three different mechanisms involved in the degradation of PMR-15 during aging at elevated temperatures. These are a weight gain, a small weight fraction bulk material weight loss, and a large mass fraction weight loss concentrated at the surface of the polymer or composite. At the higher temperatures (260 C and above), the surface loss predominates. Below 260 C, the surface loss and the bulk core loss become more equivalent. Between 175 and 260 C,

Download or read book Multiscale Modeling and Simulation of Composite Materials and Structures written by Young Kwon and published by Springer Science & Business Media. This book was released on 2007-12-04 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Stress and Damage in Polymer Matrix Composite Materials Due to Material Degradation at High Temperatures written by Hugh L. McManus and published by . This book was released on 1996 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transverse Flexural Tests as a Tool for Assessing Damage to PMR 15 Composites from Isothermal Aging in Air at Elevated Temperatures written by Kenneth J. Bowles and published by . This book was released on 1992 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Controlled Interphases in Composite Materials written by Hatsuo Ishida and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 821 pages. Available in PDF, EPUB and Kindle. Book excerpt: The third International Conference on Composite Interfaces (ICCI-III) was held under the auspecies of ASM International, The Aluminum Company of America (Alcoa), The Edison Polymer Innovation Co. (EPIC), Case Western Reserve University, Nippon Glass Fiber Co., Nitto Boseki Co., Office of Naval Reserach (ONR), SAMPE Japan, Teijin Co., Mobay Co., Union Carbide Co., and Vetrotex Sain-Gobain. The underlying philosophy of the conference continues to be the promotion of fundamental understanding of the structure and role of composite interfaces. With the growth of composite interface studies, the research direction naturally changes from characterization and understanding of interfacial structure to controlling this structure. For this reason, the conference was subtitled, "Controlled Interphase Structure." The rather unfamiliar phrase "interphase" is used to emphasize the interfacial region whose properties are different from the bulk. The importance of the interphase to the mechanochemical properties has been rapidly recognized among composite researchers in recent years. The conference incorporated nine sessions. No concurrent sessions were planned because of the strong interest among panicipants and organizers to intennix researchers from different disciplines. Papers presented were redistributed in Pans I throught V. Because of this, both the conference and proceedings are not organized based on the traditional disciplines or materials, but rather around concepts.