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Languages : en
Pages :
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Book Description
Sandia National Laboratories (SNL) designs mechanical systems with electronics that must survive high shock environments. These mechanical systems include penetrators that must survive soil and rock penetration, nuclear transportation casks that must survive transportation environments, and laydown weapons that must survive delivery impact. These mechanical systems contain electronics that may operate during and after the high shock environment and that must be protected from the high shock environments. A study has been started to improve the packaging techniques for the advanced electronics utilized in these mechanical systems because current packaging techniques are inadequate for these sensitive electronics. In many cases, it has been found that the packaging techniques currently used not only do not mitigate the shock environment but actually amplify the shock environment. An ambitious goal for this packaging study is to avoid amplification and possibly attenuate the shock environment before it reached the electronics contained in the various mechanical systems. Here, a study to compare two thickness values, 0.125 and 0.250 in. of five materials, GE RTV 630, HS II Silicone, Polysulfide Rubber, Sylgard 184, and Teflon for their shock mitigating characteristics with a split Hopkinson bar configuration has been completed. The five materials have been tested in both unconfined and confined conditions at ambient temperature and with two applied loads of 750[mu][epsilon] peak (25 fps peak) with a 100[micro]s duration, measured at 10% amplitude, and 1500[mu][epsilon] peak (50 fps peak) with a 100[micro]s duration, measured at 10% amplitude. The five materials have been tested at ambient, cold ([minus]65 F), and hot (+165 F) for the unconfined condition with the 750[mu][epsilon] peak (25 fps peak) applied load. Time domain and frequency domain analyses of the split Hopkinson bar data have been performed to compare how these materials lengthen the shock pulse, attenuate the shock pulse, reflect high frequency content in the shock pulse, and transmit energy.
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Category :
Languages : en
Pages :
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Author: Weinong W. Chen
Publisher: Springer Science & Business Media
ISBN: 1441979824
Category : Technology & Engineering
Languages : en
Pages : 390
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Book Description
The authors systematically describe the general principles of Kolsky bars, or split Hopkinson bars, which are widely used for obtaining dynamic material properties. Modifications are introduced for obtaining reliable data. Specific experiment design guidelines are provided to subject the specimen to desired testing conditions. Detailed Kolsky-bar examples are given for different classes of materials (brittle, ductile, soft, etc) and for different loading conditions (tension, torsion, triaxial, high/low temperatures, intermediate strain rate, etc). The Kolsky bars used for dynamic structural characterization are briefly introduced. A collection of dynamic properties of various materials under various testing conditions is included which may serve as a reference database. This book assists both beginners and experienced professionals in characterizing high-rate material response with high quality and consistency. Readers who may benefit from this work include university students, instructors, R & D professionals, and scholars/engineers in solid mechanics, aerospace, civil and mechanical engineering, as well as materials science and engineering.
Author:
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Category : Aeronautics
Languages : en
Pages : 934
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Author: Gabi Ben-Dor
Publisher: Springer
ISBN: 331946213X
Category : Technology & Engineering
Languages : en
Pages : 746
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Book Description
These proceedings collect the papers presented at the 30th International Symposium on Shock Waves (ISSW30), which was held in Tel-Aviv Israel from July 19 to July 24, 2015. The Symposium was organized by Ortra Ltd. The ISSW30 focused on the state of knowledge of the following areas: Nozzle Flow, Supersonic and Hypersonic Flows with Shocks, Supersonic Jets, Chemical Kinetics, Chemical Reacting Flows, Detonation, Combustion, Ignition, Shock Wave Reflection and Interaction, Shock Wave Interaction with Obstacles, Shock Wave Interaction with Porous Media, Shock Wave Interaction with Granular Media, Shock Wave Interaction with Dusty Media, Plasma, Magnetohyrdrodynamics, Re-entry to Earth Atmosphere, Shock Waves in Rarefied Gases, Shock Waves in Condensed Matter (Solids and Liquids), Shock Waves in Dense Gases, Shock Wave Focusing, Richtmyer-Meshkov Instability, Shock Boundary Layer Interaction, Multiphase Flow, Blast Waves, Facilities, Flow Visualization, and Numerical Methods. The two volumes serve as a reference for the participants of the ISSW30 and anyone interested in these fields.
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ISBN:
Category : Power resources
Languages : en
Pages : 294
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Author:
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ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 620
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Book Description
Author: T. W. Clyne
Publisher: Cambridge University Press
ISBN: 1108837891
Category : Science
Languages : en
Pages : 297
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Book Description
Discover a novel approach to the subject, providing detailed information about established and innovative mechanical testing procedures.
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ISBN:
Category :
Languages : en
Pages : 148
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Book Description
Popular Science gives our readers the information and tools to improve their technology and their world. The core belief that Popular Science and our readers share: The future is going to be better, and science and technology are the driving forces that will help make it better.
Author: Jorgen S Bergstrom
Publisher: William Andrew
ISBN: 0323322964
Category : Technology & Engineering
Languages : en
Pages : 524
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Book Description
Very few polymer mechanics problems are solved with only pen and paper today, and virtually all academic research and industrial work relies heavily on finite element simulations and specialized computer software. Introducing and demonstrating the utility of computational tools and simulations, Mechanics of Solid Polymers provides a modern view of how solid polymers behave, how they can be experimentally characterized, and how to predict their behavior in different load environments. Reflecting the significant progress made in the understanding of polymer behaviour over the last two decades, this book will discuss recent developments and compare them to classical theories. The book shows how best to make use of commercially available finite element software to solve polymer mechanics problems, introducing readers to the current state of the art in predicting failure using a combination of experiment and computational techniques. Case studies and example Matlab code are also included. As industry and academia are increasingly reliant on advanced computational mechanics software to implement sophisticated constitutive models – and authoritative information is hard to find in one place - this book provides engineers with what they need to know to make best use of the technology available. - Helps professionals deploy the latest experimental polymer testing methods to assess suitability for applications - Discusses material models for different polymer types - Shows how to best make use of available finite element software to model polymer behaviour, and includes case studies and example code to help engineers and researchers apply it to their work
