Download or read book Accelerated Tests of Environmental Degradation in Composite Materials written by Tom George Reynolds and published by . This book was released on 1998 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: High temperature polymer matrix composites are key candidates for the structural components of proposed supersonic transport aircraft. The operational environment of these vehicles exposes the airframe to harsh conditions, including temperature extremes and moisture. These environments have been seen to cause visible damage in polymer matrix composites in timescales much less than the lifetime of the vehicle. Therefore, there is an urgent requirement for accelerated testing of the key components of the environment. A first step to this goal is to identify the components of the environment responsible for the damage. The effects of a realistic moisture and thermal environment on two high temperature polymer matrix composites (PETI-5 and PIXA-M) have been investigated in this work. An extensive test program was developed to test the response of the materials to this baseline environment and its individual components: time at moisture, moisture cycling, time at temperature and thermal cycling. Mechanism-based models were used to design accelerated moisture cycles and accelerated thermal cycles in an attempt to speed up the response to these environmental factors. These accelerated cycles were also used in the test program. The results showed visible damage in the form of cracking in both materials. The PIXA-M material was found to show more damage than the PETI-5. Cracking was confined to a thin layer of material next to the exposed edge. This suggests that the environmental exposure is reducing the effective fracture toughness of the material in this layer more than in the interior. Analysis suggests that this layer is exposed to more of the environmental components and fluctuations than the material in the interior. The individual components of time at moisture and thermal cycling were seen to cause cracking, while time at temperature did not, and moisture cycling did not appear to accelerate moisture damage. The combined environments in the baseline cycle caused more damage than any one component of the cycle on its own. Evidence points to the combined effects of time at moisture and thermal cycling as being the dominant parameters causing damage, while moisture cycling controls the extent of the damaged region. Although the designed accelerated cycles were not successful in accelerating the damage from the baseline cycle, they were instrumental in establishing what were the dominant parameters. It is suggested that a promising way of accelerating the damage observed under the realistic conditions is by combining an isomoisture environment with a cyclical stress environment, which can be achieved either thermally or mechanically.

Download or read book Accelerated Tests of Environmental Degradation in Composite Materials written by TG. Reynolds and published by . This book was released on 2001 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combined moisture cycling and thermal cycling environments are known to create damage, such as cracking of material near exposed surfaces and edges, in many new materials intended for high-temperature service. Material models suggest the damage mechanisms; these models are used to design tests to (1) isolate the effects of different damage mechanisms, and (2) accelerate them. Tests are carried out in the combined environment and in its individual components: time at moisture, moisture cycling, time at temperature, and thermal cycling. Accelerated moisture cycling and thermal cycling tests are also designed and carried out. Results are presented which suggest that, for the IM7/PETI-5 and IM7/PIXA-M materials tested, time at moisture is the most important cause of microcracking damage, with thermal cycling playing some role. Moisture cycling plays a role in the distribution of damage. The models are used to reduce laminate-specific microcracking data to general design data in the form of fracture toughness versus cycle (GIc(N)) curves.

Download or read book Environmental Degradation of Industrial Composites written by Celine A Mahieux and published by Elsevier. This book was released on 2005-12-14 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thanks to their low density and tailored properties, polymer matrix composites are attractive candidates for a large number of industrial applications ranging from aerospace to transportation and energy. However, the behaviour of polymer-based materials is strongly affected by a number of environmental factors. Environmental Degradation in Industrial Composites provides vital information on the effects of environmental factors such as temperature, liquid and gas exposure, electrical fields and radiations, and how micro- and micromechanical calculations during design and manufacture must take these effects into account. The book concludes with reviews on standard and specific testing methods for the various environmental factors and their combinations, helping mechanical/materials engineers and specifiers to predict possible changes due to environmental conditions. Each chapter is supplemented by industrial case studies to help in the understanding of degradation of composites in real life situations.This book will help you to...* Understand how environmental factors lead to degradation effects in polymer matrix composite structures* Build these factors into calculations when predicting the part performance and lifetime of structures* Compare real-life situations from case studies with your predicted results* Predict probable composite behaviour with greater accuracyThis book will help you to...* Understand how environmental factors lead to degradation effects in polymer matrix composite structures* Build these factors into calculations when predicting the part performance and lifetime of structures* Compare real-life situations from case studies with your predicted results* Predict probable composite behaviour with greater accuracy

Download or read book Composite Structures written by Peter Grant and published by ASTM International. This book was released on 2000 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of the May 1999 symposium from which these 29 papers were drawn was to bring together practitioners and theoreticians in the composite structural mechanics field to better understand the needs and limitations each group works with. Papers are organized under seven general headings: str

Download or read book Accelerated Test Methods for Assessing Environmental Degradation of Composite Laminates written by W. R. Broughton and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On the Use of Accelerated Test Methods for Characterization of Advanced Composite Materials written by Thomas S. Gates and published by . This book was released on 2003 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Accelerated Environmental Degradation of GRP Composite Materials written by Power Madoda Dlamini and published by . This book was released on 2004 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Accelerated Test Methods to Determine the Long Term Behavior of Composite Highway Structures Subject to Environmental Loading written by TR. Gentry and published by . This book was released on 2006 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research on fiber-reinforced plastic composites has explored the effects of selected aqueous environments on the mechanical and physical properties of these composites. The composite materials tested were produced using the pultrusion process. Resins included in the study were polyester and vinylester. Fibers included were E-glass, carbon, and aramid. Environments considered were air, deionized water, acetic acid at two concentrations, and ammonia at two concentrations. Temperatures considered were room temperature, 50 and 80°C. Mechanical testing included tension, flexure, and short beam shear tests. Weight loss, thermogravimetric, and calorimetric measurements were made to determine whether degradation was taking place in the fiber or matrix phases of the composite. Accelerating factors for the various environments were calculated using the framework outlined in ASTM E 632, Standard Practice for Developing Accelerated Tests to Aid in the Prediction of the Service Life of Building Components and Materials. It was observed that a combination of weight loss and thermogravimetric measurements are useful in determining whether degradation in the composite is due to fiber or matrix degradation. Trends in weight loss closely parallel loss of mechanical properties in polyester/glass rods.

Download or read book Accelerated Environmental Testing of Composite Materials written by Roger Vodicka and published by . This book was released on 1998 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: Composite materials are found to lose mechanical [properties?] on exposure to aircraft operating environments. This is mainly due to absorption of moisture from humid air by the matrix material. Composite materials are extensively used by the RAAF for both major structural components on thbe F/A-18 and for bonded repairs and doublers. The performance of these materials under long-term environmental exposure is an important aspect of both aircraft certification and in the understanding of how the components will age. This report provides a broad overview of environmental effects on composite materials and methods which may be used to predict their long-term behaviour. The use of accelerated testing environments in the laboratory is an attractive proposition as it enables tests to be carried out in reduced time frames. A number of accelerated testing methodologies and their implications are outlined here. Accelerated testing can be carried out with confidence if the exposure conditions are representative and the failure modes of the materials during mechanical tests reflect those seen in service.

Download or read book Fibrous Polymeric Composites written by Bankim Chandra Ray and published by CRC Press. This book was released on 2018-05-20 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book emphasizes the scientific origin of deformation and damage of FRP composites under various environmental effects and analyses present understanding on degradation mechanisms, role of interfaces and addition of nanofillers Discusses micro-characterization of composites and interfaces, also includes micro-mechanisms and microscopic evidences to establish the structure-property correlation Elucidates advantages and limitations of FRP composites in supercritical applications

Download or read book Handbook of Environmental Degradation of Materials written by Myer Kutz and published by William Andrew. This book was released on 2012-12-31 with total page 934 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nothing stays the same for ever. The environmental degradation and corrosion of materials is inevitable and affects most aspects of life. In industrial settings, this inescapable fact has very significant financial, safety and environmental implications. The Handbook of Environmental Degradation of Materials explains how to measure, analyse, and control environmental degradation for a wide range of industrial materials including metals, polymers, ceramics, concrete, wood and textiles exposed to environmental factors such as weather, seawater, and fire. Divided into sections which deal with analysis, types of degradation, protection and surface engineering respectively, the reader is introduced to the wide variety of environmental effects and what can be done to control them. The expert contributors to this book provide a wealth of insider knowledge and engineering knowhow, complementing their explanations and advice with Case Studies from areas such as pipelines, tankers, packaging and chemical processing equipment ensures that the reader understands the practical measures that can be put in place to save money, lives and the environment. - The Handbook's broad scope introduces the reader to the effects of environmental degradation on a wide range of materials, including metals, plastics, concrete,wood and textiles - For each type of material, the book describes the kind of degradation that effects it and how best to protect it - Case Studies show how organizations from small consulting firms to corporate giants design and manufacture products that are more resistant to environmental effects

Download or read book Environmental Effects on Advanced Composite Materials written by ASTM-ASME-MPC Joint Committee on Effect of Temperature on the Properties of Metals. Aerospace Panel and published by ASTM International. This book was released on 1976 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Carbon Nanotube Enhanced Aerospace Composite Materials written by A. Paipetis and published by Springer Science & Business Media. This book was released on 2012-09-14 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: The well documented increase in the use of high performance composites as structural materials in aerospace components is continuously raising the demands in terms of dynamic performance, structural integrity, reliable life monitoring systems and adaptive actuating abilities. Current technologies address the above issues separately; material property tailoring and custom design practices aim to the enhancement of dynamic and damage tolerance characteristics, whereas life monitoring and actuation is performed with embedded sensors that may be detrimental to the structural integrity of the component. This publication explores the unique properties of carbon nanotubes (CNT) as an additive in the matrix of Fibre Reinforced Plastics (FRP), for producing structural composites with improved mechanical performance as well as sensing/actuating capabilities. The successful combination of the CNT properties and existing sensing actuating technologies leads to the realization of a multifunctional FRP structure. The current volume presents the state of the art research in this field. The contributions cover all the aspects of the novel composite systems, i.e. modeling from nano to macro scale, enhancement of structural efficiency, dispersion and manufacturing, integral health monitoring abilities, Raman monitoring, as well as the capabilities that ordered carbon nanotube arrays offer in terms of sensing and/or actuating in aerospace composites.

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 Durability of Composites in a Marine Environment 2 written by Peter Davies and published by Springer. This book was released on 2017-09-18 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents selected papers from the 2nd Workshop on “Durability of Composites in a Marine Environment”, which was held in Brest, France in August 2016. Providing an overview of the state of the art in predicting the long-term durability of composite marine structures, it addresses modelling water diffusion; damage induced by water accelerated testing, including durability in design; in-service experiences; ocean energy; and offshore applications. Ensuring long-term durability is not only necessary for safety reasons, but also determines the economic viability of future marine structures, and as such, the book is essential reading for all those involved with composites in the marine industry, from initial design and calculation through to manufacture and service exploitation. It also provides information unavailable elsewhere on the mechanisms involved in degradation and how to take account of them.

Download or read book Proceedings of the 11th International Conference on Composite Materials written by Murray L. Scott and published by Woodhead Publishing. This book was released on 1997 with total page 976 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