Download or read book Transverse Impact of Ballistic Fibers and Yarns written by Subramani Sockalingam and published by . This book was released on 2016 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ballistic impact onto flexible textile fabrics is a complicated multi-scale problem owing to the structural hierarchy of the materials, anisotropic material behavior, projectile geometry, impact velocity and boundary conditions. While this subject has been an active area of research for decades, the fundamental mechanisms such as material failure, dynamic response and multi-axial loading occurring at lower length scales during impact are not well understood. This work provides new insights into the fundamental deformation and failure mechanisms during ballistic impact onto textile fabrics at the micron length scale. In this research, a hybrid computational-experimental systematic approach is adopted to understand the mechanisms and deformation modes of high performance polymer fibers, specifically Kevlar KM2, that is widely used in ballistic impact applications. Fiber length-scale 3D finite element (FE) models are developed to better understand and complement the complicated transverse impact experiments. The fiber length-scale study suggests that fibers are subjected to multiaxial stress states including transverse compression, axial tension, axial compression and transverse shear significant enough to cause fibrillation in the fiber during impact. A dispersive flexural wave mode is predicted by the model due to the finite longitudinal shear modulus of the fiber. The flexural wave induces curvature in the fiber significant enough to cause compressive kinking and, in turn, local fibrillation in the fiber. A fiber length-scale yarn model is developed by explicitly modeling all the 400 fibers in a KM2 600 denier yarn. The yarn transverse compression results show that fiber-fiber contact plays a significant role in the spreading and deformation of individual fibers that is consistent with experimental results. When subjected to transverse impact, the model indicates significant transverse compressive strains in the fiber that increase with impact velocity and a flexural wave that induces curvatures in the fibers significant enough to induce compressive kinking and fibrillation. In addition to the transverse wave, a spreading wave develops due to fiber-fiber contact interaction that spreads the fibers to a large extent resulting in non-uniform loading and progressive failure of fibers within the yarn. Guided by the computational models, single-fiber micromechanical experiments for axial compressive kinking and transverse compression deformation modes are developed. The average tensile strength of the kinked fibers is found to be reduced by 7% compared to the virgin fibers. An experimental methodology is developed to determine the single fiber constitutive behavior in quasi-static transverse compression by removing the geometric nonlinearity due to the growing contact area. The fibers exhibit nonlinear inelastic behavior under large compressive strains. The fibers subjected to 60% nominal strains (80% true strains) showed a 20% reduction in average tensile strength compared to the virgin fibers. A nonlinear inelastic constitutive model is implemented as a user defined material (UMAT) suitable for the commercial FE code LS-DYNA explicit analysis. During impact, the inelastic behavior results in a significant reduction in the fiber bounce velocity and a reduction in the projectile-fiber contact forces by 40% compared to an elastic constitutive behavior. The inelastic dissipation and reduced bounce leads to an inelastic collision rather than an elastic collision. The longitudinal shear modulus and the inelastic behavior are found to govern the failure response of the fibers during impact. Modeling the single fiber quasi-static multiaxial loading experiments indicate fiber failure may be initiated based on a gage length dependent maximum axial tensile strain in the fiber. Regardless of the material behavior (elastic or inelastic), fiber length-scale impact models show a gradient in the axial tensile strain (stress) in the fiber cross section at the location of failure consistent with multiaxial loading experimental observations. Fiber-level yarn breaking speed predictions based on a maximum axial tensile strain (stress) criterion are much lower than the breaking speed based on classical theory and they are consistent with experimental measurements. Therefore, the reduction in experimental yarn breaking speed compared to theoretical Smith solution is attributed to the stress concentration and property degradation mechanisms due to multiaxial stress states at the location of failure.

Download or read book Effect of Twist on Transverse Impact Response of Ballistic Fiber Yarns written by and published by . This book was released on 2015 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Hopkinson bar was employed to conduct transverse impact testing of twisted Kevlar KM2 fiber yarns at the same impact speed. The speed of Euler transverse wave generated by the impact was measured utilizing a high speed digital camera. The study included fiber yarns twisted by different amounts. The Euler transverse wave speed was observed to increase with increasing amount of twist of the fiber yarn, within the range of this investigation. As a result, the higher transverse wave speeds in the more twisted fiber yarns indicate better ballistic performance in soft body armors for personal protection.

Download or read book BALLISTICS 2016 written by Clive Woodley and published by DEStech Publications, Inc. This book was released on 2016-05-22 with total page 1277 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents high-level research on various caliber guns, cannon, mortars, drones, warheads, shells, bullets, drills and other launchers and penetrants, as well as their impact effects on natural and designed materials, including large-scale targets and body armors Provides new modeling and test data on projectile design and guidance, propellants, charges and explosives for military, aerospace and civil engineering applicationsOver 250 presentations in two printed volumes, plus searchable CD This book makes available original ballistics technology from around the world on a wide variety of weapons and their effects, including the design and trajectory/stability control of dozens of projectiles ranging from shells to missiles. The book's authors discuss the efficacy and development of propellants, munitions, and igniters and offer new approaches for modeling and testing. Also investigated in Volume 1 are shielding and protection strategies for individual persons and other targets. Volume 2 offers research on the mechanical behavior of multiple types of explosives, as well as impact and penetration data from projectile effects on surfaces ranging from natural phenomena such as water and soils to metallic plating and material-engineered armors. Papers in these volumes were presented at a conference organized by the National Defense Industrial Association (NDIA) with the International Ballistics Society.

Download or read book Advanced Fibrous Composite Materials for Ballistic Protection written by Xiaogang Chen and published by Woodhead Publishing. This book was released on 2016-01-21 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Fibrous Composite Materials for Ballistic Protection provides the latest information on ballistic protection, a topic that remains an important issue in modern times due to ever increasing threats coming from regional conflicts, terrorism, and anti-social behavior. The basic requirements for ballistic protection equipment are first and foremost, the prevention of a projectile from perforating, the reduction of blunt trauma to the human body caused by ballistic impact, the necessity that they are thermal and provide moisture comfort, and that they are lightweight and flexible to guarantee wearer’s mobility. The main aim of this book is to present some of the most recent developments in the design and engineering of woven fabrics and their use as layering materials to form composite structures for ballistic personal protection. Chapter topics include High Performance Ballistic Fibres, Ultra-High Molecular Weight Polyethylene (UHMWPE), Ballistic Damage of Hybrid Composite Materials, Analysis of Ballistic Fabrics and Layered Composite Materials, and Multi-Scale Modeling of Polymeric Composite Materials for Ballistic Protection. Contributions from leading experts in the field Cutting edge developments on the engineering of ballistic materials Comprehensive analysis of the development and uses of advanced fibrous composite materials

Download or read book Ballistics 2011 written by Ernest Baker and published by DEStech Publications, Inc. This book was released on 2011-09 with total page 2230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes papers that were first presented at a September 2011 conference organized by the National Defense Industrial Association and the International Ballistics Society. This title includes a CD-ROM that displays figures and illustrations in articles in full color along with a title screen and main menu screen.

Download or read book Advances in Experimental Impact Mechanics written by Bo Song and published by Elsevier. This book was released on 2021-08-25 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summarizing the latest advances in experimental impact mechanics, this book provides cutting-edge techniques and methods for designing, executing, analyzing, and interpreting the results of experiments involving the dynamic responses of materials and structures. It provides tailored guidelines and solutions for specific applications and materials, covering topics such as dynamic characterization of metallic materials, fiber-like materials, low-impedance materials, concrete and more. Damage evolution and constitutive behavior of materials under impact loading, one-dimensional strain loading, intermediate and high strain rates, and other environmental conditions are discussed, as are techniques using high temperature testing and miniature Kolsky bars. Provides cutting-edge techniques and methods for designing, executing, analyzing, and interpreting the results of experimental impact mechanics Covers experimental guidelines and solutions for an array of different materials, conditions, and applications Enables readers to quickly design and perform their own experiments and properly interpret the results Looks at application-specific post-test analysis

Download or read book American Society of Composites 28th Technical Conference written by Charles Bakis and published by DEStech Publications, Inc. This book was released on 2013-11-01 with total page 1892 pages. Available in PDF, EPUB and Kindle. Book excerpt: New and unpublished U.S. and international research on multifunctional, active, biobased, SHM, self-healing composites -- from nanolevel to large structures New information on modeling, design, computational engineering, manufacturing, testing Applications to aircraft, bridges, concrete, medicine, body armor, wind energy This fully searchable CD-ROM contains 135 original research papers on all phases of composite materials. The document provides cutting edge research by US, Canadian, and Japanese authorities on matrix-based and fiber composites from design to damage analysis and detection. Major divisions of the work include: Structural Health Monitoring, Multifunctional Composites, Integrated Computational Materials Engineering, Interlaminar Testing, Analysis-Shell Structures, Thermoplastic Matrices, Analysis Non-classical Laminates, Bio-Based Composites, Electrical Properties, Dynamic Behavior, Damage/Failure, Compression-Testing, Active Composites, 3D Reinforcement, Dielectric Nanocomposites, Micromechanical Analysis, Processing, CM Reinforcement for Concrete, Environmental Effects, Phase-Transforming, Molecular Modeling, Impact.

Download or read book Composite Solutions for Ballistics written by Yasir Nawab and published by Woodhead Publishing. This book was released on 2021-08-05 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: Academic researchers who are working on the development of composite materials for ballistic protection need a deeper understanding on the theory of material behavior during ballistic impact. Those working in industry also need to select proper composite constituents, to achieve their desired characteristics to make functional products. Composite Solutions for Ballistics covers the different aspects of ballistic protection, its different levels and the materials and structures used for this purpose. The emphasis in the book is on the application and use of composite materials for ballistic protection. The chapters provide detailed information on the various types of impact events and the complexity of materials to respond to those events. The characteristics of ballistic composites and modelling and simulation results will enable the reader to better understand impact mechanisms according to the theory of dynamic material behavior. A complete description of testing conditions is also given that includes sensors and high-speed devices to monitor ballistic events. The book includes detailed approaches and schemes that can be implemented in academic research into solutions for ballistic protection in both theoretical and experimental fields, to find solutions for existing and next generation threats. The book will be an essential reference resource for materials scientists and engineers, and academic and industrial researchers working in composite materials and textiles for ballistic protection, as well as postgraduate students on materials science, textiles and mechanical engineering courses. Discusses the fundamentals of impact response mechanisms and related solutions covering advantages and disadvantages for both existing and next generation applications Includes various methods for evaluation of ballistic constituents according to economic and environmental criteria, types of green ballistics are considered to enhance sustainable production of applications as well as hybrid composites from natural wastes Discusses selection methodologies for ballistic applications and detailed information on the use of textiles for reinforcement fabrication

Download or read book Dynamic Effects in Composites written by Dahsin Liu and published by DEStech Publications, Inc. This book was released on 2012 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: Book comprises multiple investigations into dynamic loading's effects on composite materials. With approaches ranging from weight drop to high-velocity and high-impact testing, as well as FEM and other analytic techniques, leading researchers explain damage, delamination and other effects in a variety of composites types and configurations.

Download or read book Protective Armor Engineering Design written by Magdi El Messiry and published by CRC Press. This book was released on 2019-09-24 with total page 357 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is increasing interest in the area of protective vests, either for protection against bullets or protection from the most realistic threats within domestic frontline operations: edged weapon, knives, and medical needles. This volume addresses that need. This new book provides an in-depth survey of the state-of-the-art research and practical techniques in the area of protected fabrics, especially stab-resistant and bulletproof fabrics. The book covers: • The history of protective armor: the long history of the art of protective armor manufacturing. • Materials used for body armor: the design and materials used for soft armor to increase its perforation-resistance utilizing high-performance fibers. • Anti-stab and anti-bullet armor design: the different design parameters required for the design of flexible armor in order to stop high-velocity projectiles. • The comfort of the body armor design: the flexibility, thermal resistivity, and evaporative moisture resistivity through the fabric. • Methods of testing the flexible body armors: testing the components of flexible body armor, according to the level of the protection required, such as NIJ Standards, HOSDB Body Armour Standards for UK Police, and the German SK1 Standard, among others. Written by an expert in textile composite material engineering, this volume fills an important gap in the area of protective fabric against stabbing or bullets and provides invaluable practical knowledge for body armor design.

Download or read book Computational Methods for Plasticity written by Eduardo A. de Souza Neto and published by John Wiley & Sons. This book was released on 2011-09-21 with total page 718 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subject of computational plasticity encapsulates the numerical methods used for the finite element simulation of the behaviour of a wide range of engineering materials considered to be plastic – i.e. those that undergo a permanent change of shape in response to an applied force. Computational Methods for Plasticity: Theory and Applications describes the theory of the associated numerical methods for the simulation of a wide range of plastic engineering materials; from the simplest infinitesimal plasticity theory to more complex damage mechanics and finite strain crystal plasticity models. It is split into three parts - basic concepts, small strains and large strains. Beginning with elementary theory and progressing to advanced, complex theory and computer implementation, it is suitable for use at both introductory and advanced levels. The book: Offers a self-contained text that allows the reader to learn computational plasticity theory and its implementation from one volume. Includes many numerical examples that illustrate the application of the methodologies described. Provides introductory material on related disciplines and procedures such as tensor analysis, continuum mechanics and finite elements for non-linear solid mechanics. Is accompanied by purpose-developed finite element software that illustrates many of the techniques discussed in the text, downloadable from the book’s companion website. This comprehensive text will appeal to postgraduate and graduate students of civil, mechanical, aerospace and materials engineering as well as applied mathematics and courses with computational mechanics components. It will also be of interest to research engineers, scientists and software developers working in the field of computational solid mechanics.

Download or read book The Response of Woven Textile Materials to Transverse Ballistic Impact written by C. R. Cork and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Functional and Technical Textiles written by Subhankar Maity and published by Elsevier. This book was released on 2023-01-30 with total page 862 pages. Available in PDF, EPUB and Kindle. Book excerpt: Functional and Technical Textiles covers recent advances in technology, properties and performance of high-tech yarns and structures and their applications in different sectors of the smart and technical textile fields. Applications, including many that go beyond apparel, where high tech and functional structural fabrics are used as reinforcements for composites, medical implants and geotextiles are covered. The book also describes the latest technologies for producing versatile products for these diversified applications. Finally, the book makes a survey of the latest research in technical textiles and its various structures, properties and applications in composites, medical textiles, geotextiles, industrial textiles, and more. Draws on the latest industry innovations for the production of new smart and technical textile functionality Explains best practice for testing and for the quality control of technical textiles Provides definitions of key terminologies used in the field and explains the differences between smart and technical textiles

Download or read book Modern Impact and Penetration Mechanics written by James D. Walker and published by Cambridge University Press. This book was released on 2021-04-22 with total page 695 pages. Available in PDF, EPUB and Kindle. Book excerpt: Indispensable treatise on the mechanics of extreme dynamic events, including impact, shocks, penetration and high-rate material response.

Download or read book Fracture Fatigue Failure and Damage Evolution Volume 3 written by Shuman Xia and published by Springer Nature. This book was released on 2021-03-26 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: ​Fracture, Fatigue, Failure and Damage Evolution, Volume 3 of the Proceedings of the 2020 SEM Annual Conference & Exposition on Experimental and Applied Mechanics, the third volume of seven from the Conference, brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on a wide range of areas, including: Novel Experimental Methods Extreme Environments Interfacial Fracture Integration of Models & Experiments Mechanics of Energy & Energetic Materials Integration of Models & Experiments In Situ Techniques for Fatigue & Fracture Microscale & Microstructural Effects on Mechanical Behavior

Download or read book Lightweight Ballistic Composites written by Ashok Bhatnagar and published by Woodhead Publishing. This book was released on 2006-06-30 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ballistic composites need to be lightweight and durable as well as exhibiting high impact resistance and damage tolerance. This important book reviews these requirements, how the materials used for ballistic composites meet them and their range of applications.After an introductory chapter, Lightweight ballistic composites is split into two main sections. The first part of the book explores material requirements and testing. There are chapters on bullets and bullet fragments, material responses to ballistic impact, standards and specifications, modelling and test methods. Part Two reviews the range of materials used, production methods and applications. Topics discussed include high-performance ballistic fibres and ceramics, non-woven ballistic and prepreg composites, and their uses in body armour, vehicle and aircraft protection.This major book is the first of its kind to give a comprehensive review of the current use of lightweight ballistic composites in both military and law-enforcement applications. It is an invaluable reference for all those involved in personnel and vehicle protection in defence and police forces around the world. Reviews the current use of lightweight ballistic composites in both military and law-enforcement application An authoritative overview of the range of materials used, production methods and applications Explores material requirements and testing

Download or read book Ballistic Materials and Penetration Mechanics written by Roy Laible and published by Elsevier. This book was released on 2012-12-02 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ballistic Materials and Penetration Mechanics deals with ballistically protective materials and penetration mechanics. The book discusses historical and practical considerations of ballistic protection, including metallic armor, as well as ballistic testing methodology, the ability of a protective material to stop or slow down a particular projectile, and the theoretical aspects of penetration mechanics. It also highlights the importance of stress wave analysis in the penetration and spalling phenomena. Organized into 12 chapters, this volume begins with an overview of the history of the armor and the modern helmet. It proceeds with a discussion of variations in ballistic test methods, errors in test methods, and the importance of the hardness and geometry of both the target and the projectile. The next chapters focus on the importance of fibrous armor, materials that are visually transparent and resistant to penetration by high-energy projectiles and fragments, and transparent armor and ceramic composite armor. The reader is also introduced to materials used in the design of metallic armor, the role of stress waves in the penetration problem, and the use of computer simulation to analyze ballistic impact experiments. The book looks at numerical techniques for modeling hypervelocity impact and concludes with a chapter on the penetration mechanics of textile structures. This book is a valuable resource for scientists working at government, industrial, and university laboratories, as well as law enforcement officers and others who want information on materials that provide the best protection against damage from impacts, explosions, and bullets.