Download or read book Effects of Material and Manufacturing Variations on Dimensionally Stable Composite Structure written by Erik Abernathy and published by . This book was released on 1995 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dimensional stability is an important consideration for space structures such as antennas, optical platforms, and support structures. Composites offer the major advantage of tailorable coefficients of thermal expansion (CTE's). Theoretically, zero-CTE composite structures can be designed, but in practice the CTE's deviate from zero due to variations in materials and manufacturing techniques. An analytical technique has been developed to find both the inplane CTE's ([alpha]) and the analogous coefficients of out-of-plane thermal bending and warping (WT). Both the mean values and, more significantly, the standard deviations of these values are computed, based on statistical information about the materials and manufacturing processes used. In the case of laminates designed with zero mean values, these standard deviations are the performance metrics. An extensive experimental program has been carried out to verify the models. In addition to data collected from the literature, both unsymmetric laminates (with non-zero mean thermally induced out-of-plane deformation) and symmetric laminates (which in theory do not deform out of plane, but in practice do, due to manufacturing and material variations) were exposed to varying temperatures and their out-of-plane deformations measured. The analysis was used parametrically to find laminates with both minimized mean values and low standard deviations of the thermal expansion coefficients. The analysis was also used in sensitivity analyses to identify manufacturing factors and material properties that are most important to minimizing thermally induced deformations.

Download or read book American Society of Composites Tenth Technology Proceedings written by Amer Society Composi and published by CRC Press. This book was released on 1995-10-17 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conference proceedings from the American Society of Composites, Tenth Technology Proceedings: Composite Materials, Mechanics and Processing on October 18-20, 1995 at the Miramar Sheraton Hotel Santa Monica, California

Download or read book Introduction to the Dimensional Stability of Composite Materials written by Ernest G. Wolff and published by DEStech Publications, Inc. This book was released on 2004 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a comprehensive introduction to the quantitative analysis of dimensional instability in composite materials. It will aid in predicting deformations in a wide range of composite materials products and parts, under mechanical, thermophysical, and environmental stresses over time.

Download or read book Composite Structures written by Rani Elhajjar and published by John Wiley & Sons. This book was released on 2018-09-25 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents the latest strategies in the development and use of composite materials for large structures and the effects of defects Practical Design and Validation of Composites Structures: Effects of Defects offers an important guide to the use of fiber-reinforced composites and how they affect the durability and safety of engineering structures such as aircraft, ships, bridges, wind turbines as well as sporting equipment. The text draws on the authors’ direct experience in industry and academia to cover the most recent strategies in the development of composite structures and uniquely integrates the assessment of the effects of defects introduced during production. This comprehensive resource builds on an essential introduction to the characteristics of composites and the most common types of defects encountered in production. The authors review the recent manufacturing methods and technologies used for inspecting composite structures and the design issues related to an analysis of their failure and strength incorporating the variability of processing. The text also contains information on the latest regulatory requirements and the relevant standards associated with the testing and design within a robust design philosophy and approach. This important resource: Offers a comprehensive review of the most current regulatory developments in the use of composites for the construction of complex composite structures Presents information on the basic characteristics of composites Includes testing strategies for determining the impacts of production defects Reviews the most current manufacturing methods and inspection technologies in the field Contains methods for statistical analysis and processing of experimental effects of defects test data Written for professional engineers in mechanical engineering, automotive engineering, aerospace engineering, civil engineering, and energy engineering as well as industry and academic researchers, Practical Design and Validation of Composites Structures: Effects of Defects is the hands-on text that covers the essential information needed to understand the use of composites and how they affect complex engineering projects using composites.

Download or read book Probabilistic Analysis and Design of Dimensionally Stable Composite Structures written by Erik Abernathy and published by . This book was released on 1995 with total page 586 pages. Available in PDF, EPUB and Kindle. Book excerpt: Objects in orbit are exposed to extreme temperatures. These can lead to deformations which complicate the design of dimensionally critical space structures. Composites offer the major advantage of tailorable properties. Theoretically, dimensionally stable composite laminates can be made with coefficients of thermal expansion (CTE's) of zero. In practice, the laminate properties deviate from predicted properties due to variations in material properties and manufacturing parameters. The goal of the present investigation is to develop an analytical methodology to predict means and standard deviations of laminate engineering properties from given means and standard deviations of ply material properties, fiber volume fractions, and manufacturing parameters. This objective is successfully met through a combination of analytical modeling and experimental investigation. In the analysis, the means and standard deviations of the laminate properties are found using Classical Laminated Plate Theory (CLPT) and simple statistical methods. A new laminate property, the thermal bending coefficient, is defined. The thermal bending coefficient is the out-of-plane analog to the in-plane CTE. Many unsymmetric laminates exhibit large-deformation effects which depart from CLPT predictions. These effects are accounted for in a separate analysis using an energy method. The analyses are implemented in a set of computer codes which can analyze any user-defined laminate. Extensive experimental results provide verification of the analyses. Ninety specimens, from eighteen AS4/3501-6 graphite/epoxy panels with sixteen different layups, are tested to investigate the effects of ply angle, ply grouping, thickness, zero degree plies, and asymmetry on the thermal bending coefficients. Specimens are mounted in a thermal environment chamber, and deflections at chamber temperatures of 25°C and 100° C are measured by two laser displacement sensors. The data is reduced to find the thermal bending coefficients of the specimens. Correlations between experimental results and the analyses are generally very good. The analytical predictions bracket the data in most cases. Most predicted trends are seen in the experimental data. Parametric studies are also conducted. The variations of the laminate properties, and their sensitivities to the input parameters, are found to be very dependent on the laminate considered. The computer code which implements the analytical model is a useful design tool. It can be used to conduct trade studies, and to find which parameters are most important to control in order to maintain low standard deviations of critical laminate properties.

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1998 with total page 980 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the Annual AIAA USU Conference on Small Satellites written by and published by . This book was released on with total page 860 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book American Society for Composites Eighth Proceedings written by American Society for Composites. Technical Conference and published by CRC Press. This book was released on 1993-10-15 with total page 1168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Space Station Systems written by and published by . This book was released on 1987 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Research in Materials written by Massachusetts Institute of Technology and published by . This book was released on 1996 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Review of Dimensional Instability in Metals written by Robert Edward Maringer and published by . This book was released on 1966 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Federal Register written by and published by . This book was released on 2000-06-08 with total page 1268 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fundamentals of Composite Processing written by and published by . This book was released on 2004 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: USDA Forest Service, Forest Products Laboratory (Madison, Wisconsin) and the Wood-Based Composites Center of Virginia Tech (Blacksburg, Virginia) co-sponsored a conference, held November 5-6, 2003, in Madison, Wisconsin, on the fundamentals of composite processing. The goals were to assess what we know, define what we need to know, and then establish the state of the art in hot-pressing of wood-based, particulate composites. Academic and industrial professionals from around North America and Europe were invited to participate because of their expertise and interest in this area of research. The workshop covered four critical topics associated with hot-pressing of composites: resin curing and bonding, press control, physics of hotpressing, and computer simulations of the pressing process.‍?This report is the official record of the presentations and discussions that occurred during this workshop.

Download or read book Technology for Large Space Systems written by and published by . This book was released on 1989 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Collection of Technical Papers written by and published by . This book was released on 1996 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1973 with total page 1142 pages. Available in PDF, EPUB and Kindle. Book excerpt: