Download or read book Structure Processing Property Relationships at the Fiber Matrix Interface in Electron Beam Cured Composite Materials written by and published by . This book was released on 1998 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this project was to characterize the properties of the resin and the fiber- resin interface in electron beam cured materials by evaluating several structural and processing parameters. The Oak Ridge National Laboratory (ORNL) has recently determined that the interlaminar shear strength properties of electron beam cured composites were 19-28% lower than for autoclave cured composites. Low interlaminar shear strength is widely acknowledged as the key barrier to the successfid acceptance and implementation of electron beam cured composites in industry. In this project we found that simple resin modification and process improvements are unlikely to substantially improve the interlaminar shear strength properties of electron beam cured composites. However, sizings and coatings were shown to improve these properties and there appears to be significant potential for further improvement. In this work we determined that the application of epoxy-based, electron beam compatible sizings or coatings onto surface- treated, unsized carbon fibers improved the composite interlaminar shear strength by as much as 55% compared to composites fabricated from surface-treated, unsized carbon fibers and 11 YO compared to composites made from surface-treated, GP sized carbon fibers. This work has identified many promising pathways for increasing the interlaminar shear strength of electron beam cured composites. As a result of these promising developments we have recently submitted a U.S. Department of Energy-Energy Research (DOE-ER) sponsored Laboratory Technical Research-Cooperative Research and Development Agreement (LTR- CRADA) proposal entitled, "Interracial Properties of Electron Beam Cured Composites", to continue this work. If funded, ORNL will lead a 3-year, $2.6 million effort involving eight industrial partners, NASA-Langley, and the U.S. Air Force. The principal objective of this CRADA is to significantly improve the interracial properties of carbon-fiber-reinforced composites beyond the current state-of-the art electron beam cured composites for use in several DOE, DoD, and industrial applications. In addition, several papers from this Laboratory Director's Research and Development (LDRD) project will be submitted to the Society for the Advancement of Materials and Process Engineering for oral presentations and publications.

Download or read book High Performance Structural Fibers for Advanced Polymer Matrix Composites written by National Research Council and published by National Academies Press. This book was released on 2005-05-09 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: Military use of advanced polymer matrix composites (PMC)â€"consisting of a resin matrix reinforced by high-performance carbon or organic fibersâ€"while extensive, accounts for less that 10 percent of the domestic market. Nevertheless, advanced composites are expected to play an even greater role in future military systems, and DOD will continue to require access to reliable sources of affordable, high-performance fibers including commercial materials and manufacturing processes. As a result of these forecasts, DOD requested the NRC to assess the challenges and opportunities associated with advanced PMCs with emphasis on high-performance fibers. This report provides an assessment of fiber technology and industries, a discussion of R&D opportunities for DOD, and recommendations about accelerating technology transition, reducing costs, and improving understanding of design methodology and promising technologies.

Download or read book Engineered Interfaces in Fiber Reinforced Composites written by Jang-Kyo Kim and published by Elsevier. This book was released on 1998-10-21 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study and application of composite materials are a truly interdisciplinary endeavour that has been enriched by contributions from chemistry, physics, materials science, mechanics and manufacturing engineering. The understanding of the interface (or interphase) in composites is the central point of this interdisciplinary effort. From the early development of composite materials of various nature, the optimization of the interface has been of major importance. While there are many reference books available on composite materials, few of them deal specifically with the science and mechanics of the interface of fiber reinforced composites. Further, many recent advances devoted solely to research in composite interfaces have been scattered in a variety of published literature and have yet to be assembled in a readily accessible form. To this end this book is an attempt to bring together recent developments in the field, both from the materials science and mechanics perspective, in a single convenient volume. The central theme of the book is tailoring the interface properties to optimise the mechanical peformance and structural integrity of composites with enhanced strength/stiffness and fracture toughness (or specific fracture resistance). It deals mainly with interfaces in advanced composites made from high performance fibers, such as glass, carbon, aramid, ultra high modulus polyethylene and some inorganic (e.g. B/W, A12O3, SiC) fibers, and matrix materials encompassing polymers, metals/alloys and ceramics. The book is intended to provide a comprehensive treatment of composite interfaces in such a way that it should be of interest to materials scientists, technologists and practising engineers, as well as graduate students and their supervisors in advanced composites. We hope that this book will also serve as a valuable source of reference to all those involved in the design and research of composite interfaces. The book contains eight chapters of discussions on microstructure-property relationships with underlying fundamental mechanics principles. In Chapter 1, an introduction is given to the nature and definition of interfaces in fiber reinforced composites. Chapter 2 is devoted to the mechanisms of adhesion which are specific to each fiber-matrix system, and the physio-chemical characterization of the interface with regard to the origin of adhesion. The experimental techniques that have been developed to assess the fiber-matrix interface bond quality on a microscopic scale are presented in Chapter 3, along with the techniques of measuring interlaminar/intralaminar strengths and fracture toughness using bulk composite laminates. The applicability and limitations associated with loading geometry and interpretation of test data are compared. Chapter 4 presents comprehensive theoretical analyses based on shear-lag models of the single fiber composite tests, with particular interest being placed on the interface debond process and the nature of the fiber-matrix interfacial bonding. Chapter 5 is devoted to reviewing current techniques of fiber surface treatments which have been devised to improve the bond strength and the fiber-matrix compatibility/stability during the manufacturing processes of composites. The micro-failure mechanisms and their associated theories of fracture toughness of composites are discussed in Chapter 6. The roles of the interface and its effects on the mechanical performance of fiber composites are addressed from several viewpoints. Recent research efforts to augment the transverse and interlaminar fracture toughness by means of controlled interfaces are presented in Chapters 7 and 8.

Download or read book The Characterization of the Structure Property Relations of Electron Beam Cured Composites written by and published by . This book was released on 2004 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ultimate objective of this program was to develop a fundamental understanding of the relations between the processing parameters, the resultant physical and chemical structure and the performance of E-beam cured polymer matrix composites for cryogenic fuel containment structures for future Air Force space operations vehicles. The S-beam induced cure mechanisms for cationic polymerized epoxides and free radical polymerized bismaleimides (BMI) were characterized in terms of processing variables, dissociation chemistry of the catalytic initiators, and inherent absorbed moisture. A general S-beam resin and composite cure model was developed as a function of S-beam processing variables. Stress-thermal cycling of BMI- Carbon fiber composites under cryogenic fuel simulated environments revealed that there is a high probability of microcracking with increasing number of thermo-cycles, higher pre-strain and humidity.

Download or read book Fiber Matrix Interface Studies on Electron Beam Cured Composites written by and published by . This book was released on 1999 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The recently completed Department of Energy (DOE) and industry sponsored Cooperative Research and Development Agreement (CRADA) entitled, ''Electron Beam Curing of Polymer Matrix Composites, '' determined that the interlaminar shear strength properties of the best electron beam cured IM7/epoxy composites were 19-28% lower than autoclave cured IM7/epoxy composites (i.e. IM7/977-2 and IM7/977-3). Low interlaminar shear strength is widely acknowledged as the key barrier to the successful acceptance and implementation of electron beam cured composites in the aircraft/aerospace industry. The objective of this work was to improve the interlaminar shear strength properties of electron beam cured composites by formulating and evaluating several different fiber sizings or coating materials. The researchers have recently achieved some promising results by having discovered that the application of epoxy-based, electron beam compatible sizings or coatings onto surface-treated, unsized IM7 carbon fibers improved the composite interlaminar shear strength properties by as much as 55% versus composites fabricated from surface-treated, unsized IM7 fibers. In addition, by applying these same epoxy-based sizings or coatings onto surface-treated, unsized IM7 fibers it was possible to achieve an 11% increase in the composite interlaminar shear strength compared to composites made from surface-treated, GP-sized IM7 fibers. Work is continuing in this area of research to further improve these properties.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Interfacial Structure Property Relationships at the Fiber Matrix Interphase in Advanced Composites written by Lawrence T. Drzal and published by . This book was released on 1987 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interfacial structure property relationships at the fiber matrix interphase in advanced composite materials. This grant approved under the DOD University Research Instrumentation Grant Program was used to partially fund the purchase of surface spectroscopy equipment. The report contains the listings and descriptions of equipment actually acquired, a summary of research projects on which the equipment will be used, and other research work of interest to DOD for which this equipment will be used. Keywords: Metal matrix composite, Carbon fiber composites, Ceramic matrix composites.

Download or read book Fiber Matrix and Interface Properties written by Christopher J. Spragg and published by ASTM International. This book was released on 1996 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emphasizing fiber-matrix adhesion and its characterization in composite materials, reports results from applying the most commonly used test methods, such as fragmentation, pull-out, and indentation, to high-performance composites and their constituents. The 13 papers were presented at a symposium i

Download or read book Processing Discontinuous Fiber Polymer Composites written by Murty Narayan Vyakarnam and published by . This book was released on 1996 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book How Concept Becomes Reality written by Ray Adsit and published by . This book was released on 1991 with total page 1222 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Polymer Matrix Composites and Technology written by Ru-Min Wang and published by Elsevier. This book was released on 2011-07-14 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt: Given such properties as low density and high strength, polymer matrix composites have become a widely used material in the aerospace and other industries. Polymer matrix composites and technology provides a helpful overview of these materials, their processing and performance.After an introductory chapter, part one reviews the main reinforcement and matrix materials used as well as the nature of the interface between them. Part two discusses forming and molding technologies for polymer matrix composites. The final part of the book covers key aspects of performance, including tensile, compression, shear and bending properties as well as impact, fatigue and creep behaviour.Polymer matrix composites and technology provides both students and those in industry with a valuable introduction to and overview of this important class of materials. Provides a helpful overview of these materials, their processing and performance incorporating naming and classification of composite materials Reviews the main reinforcement and matrix materials used as well as the nature of the interface between them including damage mechanisms Discusses forming and molding technologies for polymer matrix composites outlining various techniques and technologies

Download or read book Physics Briefs written by and published by . This book was released on 1994 with total page 1118 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Processing Structure Property Relationship of Composite Interfaces Symposium written by and published by . This book was released on 1999 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book CRADA Final Report for CRADA No ORNL99 0544 Interfacial Properties of Electron Beam Cured Composites written by C. J. Janke and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Electron beam (EB) curing is a technology that promises, in certain applications, to deliver lower cost and higher performance polymer matrix composite (PMC) structures compared to conventional thermal curing processes. PMCs enhance performance by making products lighter, stronger, more durable, and less energy demanding. They are essential in weight- and performance-dominated applications. Affordable PMCs can enhance US economic prosperity and national security. US industry expects rapid implementation of electron beam cured composites in aircraft and aerospace applications as satisfactory properties are demonstrated, and implementation in lower performance applications will likely follow thereafter. In fact, at this time and partly because of discoveries made in this project, field demonstrations are underway that may result in the first fielded applications of electron beam cured composites. Serious obstacles preventing the widespread use of electron beam cured PMCs in many applications are their relatively poor interfacial properties and resin toughness. The composite shear strength and resin toughness of electron beam cured carbon fiber reinforced epoxy composites were about 25% and 50% lower, respectively, than those of thermally cured composites of similar formulations. The essential purpose of this project was to improve the mechanical properties of electron beam cured, carbon fiber reinforced epoxy composites, with a specific focus on composite shear properties for high performance aerospace applications. Many partners, sponsors, and subcontractors participated in this project. There were four government sponsors from three federal agencies, with the US Department of Energy (DOE) being the principal sponsor. The project was executed by Oak Ridge National Laboratory (ORNL), NASA and Department of Defense (DOD) participants, eleven private CRADA partners, and two subcontractors. A list of key project contacts is provided in Appendix A. In order to properly manage the large project team and properly address the various technical tasks, the CRADA team was organized into integrated project teams (IPT's) with each team focused on specific research areas. Early in the project, the end user partners developed ''exit criteria'', recorded in Appendix B, against which the project's success was to be judged. The project team made several important discoveries. A number of fiber coatings or treatments were developed that improved fiber-matrix adhesion by 40% or more, according to microdebond testing. The effects of dose-time and temperature-time profiles during the cure were investigated, and it was determined that fiber-matrix adhesion is relatively insensitive to the irradiation procedure, but can be elevated appreciably by thermal postcuring. Electron beam curable resin properties were improved substantially, with 80% increase in electron beam 798 resin toughness, and {approx}25% and 50% improvement, respectively, in ultimate tensile strength and ultimate tensile strain vs. earlier generation electron beam curable resins. Additionally, a new resin electron beam 800E was developed with generally good properties, and a very notable 120% improvement in transverse composite tensile strength vs. earlier generation electron beam cured carbon fiber reinforced epoxies. Chemical kinetics studies showed that reaction pathways can be affected by the irradiation parameters, although no consequential effects on material properties have been noted to date. Preliminary thermal kinetics models were developed to predict degree of cure vs. irradiation and thermal parameters. These models are continually being refined and validated. Despite the aforementioned impressive accomplishments, the project team did not fully realize the project objectives. The best methods for improving adhesion were combined with the improved electron beam 3K resin to make prepreg and uni-directional test laminates from which composite properties could be determined. Nevertheless, only minor improvements in the composite shear strength, and moderate improvements in the transverse tensile strength, were achieved. The project team was not satisfied with the laminate quality achieved, and low quality (specifically, high void fraction) laminates will compromise the composite properties. There were several problems with the prepregging and fabrication, many of them related to the use of new fiber treatments.

Download or read book The Effect of Processing on the Interface Structure property Relationship in a Ti 24A1 11Nb at Composite written by Paul E. Cantonwine and published by . This book was released on 1993 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Unsaturated Polyester Resins written by Sabu Thomas and published by Elsevier. This book was released on 2019-07-11 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unsaturated Polyester Resins: Fundamentals, Design, Fabrication, and Applications explains the preparation, techniques and applications relating to the use of unsaturated polyester resin systems for blends, interpenetrating polymer networks (IPNs), gels, composites and nanocomposites, enabling readers to understand and utilize the improved material properties that UPRs facilitate. Chapters cover unsaturated polyester resins and their interaction at the macro, micro and nano levels, in-depth studies on the properties and analysis of UPR based materials, and the applications of UPR based composites, blends, IPNs and gels across a range of advanced commercial and industrial fields. This is a highly detailed source of information on unsaturated polyester resins, supporting academics, researchers and postgraduate students working with UPRs, polyesters, polymeric or composite materials, polymer chemistry, polymer physics, and materials science, as well as scientists, R&D professionals and engineers in industry. Covers the use of unsaturated polyester resin systems for blends, IPNs, gels, composites and nanocomposites Presents cutting-edge techniques for the analysis and improvement of properties of advanced UPR-based materials Unlocks the potential of unsaturated polyester resins in high-performance materials for a range of advanced applications

Download or read book Interfacial Properties of Electron Beam Cured Composites written by and published by . This book was released on 1999 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of the CRADA are to: Confirm that fiber-resin adhesion is responsible for the observed poor shear properties; Determine the mechanism(s) responsible for poor adhesion between carbon fibers and epoxy resins after e-beam curing; Develop and evaluate resin systems and fiber treatments to improve the properties of e-beam cured, carbon-fiber-reinforced composites; and Develop refined methods for processing e-beam cured, carbon-fiber-reinforced composites.