Download or read book Implementation of Improved Transverse Shear Calculations and Higher Order Laminate Theory Into Strain Rate Dependent Analyses of Polymer Matrix Compos written by Lin-Fa Zhu and published by BiblioGov. This book was released on 2013-06 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: A numerical procedure has been developed to investigate the nonlinear and strain rate dependent deformation response of polymer matrix composite laminated plates under high strain rate impact loadings. A recently developed strength of materials based micromechanics model, incorporating a set of nonlinear, strain rate dependent constitutive equations for the polymer matrix, is extended to account for the transverse shear effects during impact. Four different assumptions of transverse shear deformation are investigated in order to improve the developed strain rate dependent micromechanics model. The validities of these assumptions are investigated using numerical and theoretical approaches. A method to determine through the thickness strain and transverse Poisson's ratio of the composite is developed. The revised micromechanics model is then implemented into a higher order laminated plate theory which is modified to include the effects of inelastic strains. Parametric studies are conducted to investigate the mechanical response of composite plates under high strain rate loadings. Results show the transverse shear stresses cannot be neglected in the impact problem. A significant level of strain rate dependency and material nonlinearity is found in the deformation response of representative composite specimens.
Download or read book Implementation of Improved Transverse Shear Calculations and Higher Order Laminate Theory Into Strain Rate Dependent Analyses of Polymer Matrix Composites written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: A numerical procedure has been developed to investigate the nonlinear and strain rate dependent deformation response of polymer matrix composite laminated plates under high strain rate impact loadings. A recently developed strength of materials based micromechanics model, incorporating a set of nonlinear, strain rate dependent constitutive equations for the polymer matrix, is extended to account for the transverse shear effects during impact. Four different assumptions of transverse shear deformation are investigated in order to improve the developed strain rate dependent micromechanics model. The validities of these assumptions are investigated using numerical and theoretical approaches. A method to determine through the thickness strain and transverse Poisson's ratio of the composite is developed. The revised micromechanics model is then implemented into a higher order laminated plate theory which is modified to include the effects of inelastic strains. Parametric studies are conducted to investigate the mechanical response of composite plates under high strain rate loadings. Results show the transverse shear stresses cannot be neglected in the impact problem. A significant level of strain rate dependency and material nonlinearity is found in the deformation response of representative composite specimens.Zhu, Lin-Fa and Kim, Soo and Chattopadhyay, Aditi and Goldberg, Robert K.Glenn Research CenterDEFORMATION; LAMINATES; MECHANICAL PROPERTIES; POLYMER MATRIX COMPOSITES; STRAIN RATE; MATHEMATICAL MODELS; SHEAR STRESS; CONSTITUTIVE EQUATIONS; NONLINEARITY; POISSON RATIO; PLATE THEORY; PLATES (STRUCTURAL MEMBERS); VISCOPLASTICITY
Download or read book Implementation of Laminate Theory Into Strain Rate Dependent Micromechanics Analysis of Polymer Matrix Composites written by Robert K. Goldberg and published by . This book was released on 2000 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Implementation of Laminate Theory Into Strain Rate Dependent Micromechanics Analysis of Polymer Matrix Composites written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-16 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: A research program is in progress to develop strain rate dependent deformation and failure models for the analysis of polymer matrix composites subject to impact loads. Previously, strain rate dependent inelastic constitutive equations developed to model the polymer matrix were implemented into a mechanics of materials based micromechanics method. In the current work, the computation of the effective inelastic strain in the micromechanics model was modified to fully incorporate the Poisson effect. The micromechanics equations were also combined with classical laminate theory to enable the analysis of symmetric multilayered laminates subject to in-plane loading. A quasi-incremental trapezoidal integration method was implemented to integrate the constitutive equations within the laminate theory. Verification studies were conducted using an AS4/PEEK composite using a variety of laminate configurations and strain rates. The predicted results compared well with experimentally obtained values. Goldberg, Robert K. Glenn Research Center NASA/TM-2000-210351, E-12400, NAS 1.15:210351
Download or read book Implementation of Fiber Substructuring Into Strain Rate Dependent Micromechanics Analysis of Polymer Matrix Composites written by and published by . This book was released on 2001 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rate Dependent Deformation and Strength Analysis of Polymer Matrix Composites written by and published by . This book was released on 1999 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AIAA Journal written by American Institute of Aeronautics and Astronautics and published by . This book was released on 2005 with total page 868 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1988 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rate Dependent Deformation and Strength Analysis of Polymer Matrix Composites written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-04 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: A research program is being undertaken to develop rate dependent deformation and failure models for the analysis of polymer matrix composite materials. In previous work in this program, strain-rate dependent inelastic constitutive equations used to analyze polymers have been implemented into a mechanics of materials based composite micromechanics method. In the current work, modifications to the micromechanics model have been implemented to improve the calculation of the effective inelastic strain. Additionally, modifications to the polymer constitutive model are discussed in which pressure dependence is incorporated into the equations in order to improve the calculation of constituent and composite shear stresses. The Hashin failure criterion is implemented into the analysis method to allow for the calculation of ply level failure stresses. The deformation response and failure stresses for two representative uniaxial polymer matrix composites, IM7/977-2 and AS4-PEEK, are predicted for varying strain rates and fiber orientations. The predicted results compare favorably to experimentally obtained values.Goldberg, Robert K. and Stouffer, Donald C.Glenn Research CenterPOLYMER MATRIX COMPOSITES; DEFORMATION; STRAIN RATE; FAILURE ANALYSIS; MICROMECHANICS; PRESSURE DEPENDENCE; SHEAR STRESS; FIBER ORIENTATION; FAILURE; CONSTITUTIVE EQUATIONS; CRITERIA
Download or read book Ls Dyna Implementation of Polymer Matrix Composite Model Under High Strain Rate Impact written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-20 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: A recently developed constitutive model is implemented into LS-DYNA as a user defined material model (UMAT) to characterize the nonlinear strain rate dependent behavior of polymers. By utilizing this model within a micromechanics technique based on a laminate analogy, an algorithm to analyze the strain rate dependent, nonlinear deformation of a fiber reinforced polymer matrix composite is then developed as a UMAT to simulate the response of these composites under high strain rate impact. The models are designed for shell elements in order to ensure computational efficiency. Experimental and numerical stress-strain curves are compared for two representative polymers and a representative polymer matrix composite, with the analytical model predicting the experimental response reasonably well. Zheng, Xia-Hua and Goldberg, Robert K. and Binienda, Wieslaw K. and Roberts, Gary D. Glenn Research Center NASA/TM-2003-212583, E-14123, NAS 1.15:212583
Download or read book Dynamic Deformation Damage and Fracture in Composite Materials and Structures written by Vadim Silberschmidt and published by Woodhead Publishing. This book was released on 2016-01-23 with total page 618 pages. Available in PDF, EPUB and Kindle. Book excerpt: Composite materials, with their higher exposure to dynamic loads, have increasingly been used in aerospace, naval, automotive, sports and other sectors over the last few decades. Dynamic Deformation, Damage and Fracture in Composite Materials and Structures reviews various aspects of dynamic deformation, damage and fracture, mostly in composite laminates and sandwich structures, in a broad range of application fields including aerospace, automotive, defense and sports engineering. As the mechanical behavior and performance of composites varies under different dynamic loading regimes and velocities, the book is divided into sections that examine the different loading regimes and velocities. Part one examine low-velocity loading and part two looks at high-velocity loading. Part three then assesses shock and blast (i.e. contactless) events and the final part focuses on impact (contact) events. As sports applications of composites are linked to a specific subset of dynamic loading regimes, these applications are reviewed in the final part. Examines dynamic deformation and fracture of composite materials Covers experimental, analytical and numerical aspects Addresses important application areas such as aerospace, automotive, wind energy and defence, with a special section on sport applications
Download or read book Strain Rate Dependent Modeling of Polymer Matrix Composites written by Robert K. Goldberg and published by . This book was released on 1999 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Strain Rate Dependent Deformation and Strength Modeling of a Polymer Matrix Composite Utilizing a Micromechanics Approach written by Robert Keith Goldberg and published by . This book was released on 1999 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Incorporation of Mean Stress Effects Into the Micromechanical Analysis of the High Strain Rate Response of Polymer Matrix Composites written by and published by . This book was released on 2002 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Strain Rate Deformation Modeling of a Polymer Matrix Composite Part 2 Composite Micromechanical Model written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-05 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently applications have exposed polymer matrix composite materials to very high strain rate loading conditions, requiring an ability to understand and predict the material behavior under these extreme conditions. In this second paper of a two part report, a three-dimensional composite micromechanical model is described which allows for the analysis of the rate dependent, nonlinear deformation response of a polymer matrix composite. Strain rate dependent inelastic constitutive equations utilized to model the deformation response of a polymer are implemented within the micromechanics method. The deformation response of two representative laminated carbon fiber reinforced composite materials with varying fiber orientation has been predicted using the described technique. The predicted results compare favorably to both experimental values and the response predicted by the Generalized Method of Cells, a well-established micromechanics analysis method. Goldberg, Robert K. and Stouffer, Donald C. Glenn Research Center RTOP 523-24-13...
Download or read book An Improved Transverse Shear Deformation Theory for Laminated Anisotropic Plates written by M. V. V. Murthy and published by . This book was released on 1981 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
