Download or read book Differential Continuum Damage Mechanics Models for Creep and Fatigue of Unidirectional Metal Matrix Composites written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-10-27 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three multiaxial isothermal continuum damage mechanics models for creep, fatigue, and creep/fatigue interaction of a unidirectional metal matrix composite volume element are presented, only one of which will be discussed in depth. Each model is phenomenological and stress based, with varying degrees of complexity to accurately predict the initiation and propagation of intergranular and transgranular defects over a wide range of loading conditions. The development of these models is founded on the definition of an initially transversely isotropic fatigue limit surface, static fracture surface, normalized stress amplitude function and isochronous creep damage failure surface, from which both fatigue and creep damage evolutionary laws can be obtained. The anisotropy of each model is defined through physically meaningful invariants reflecting the local stress and material orientation. All three transversely isotropic models have been shown, when taken to their isotropic limit, to directly simplify to previously developed and validated creep and fatigue continuum damage theories. Results of a nondimensional parametric study illustrate (1) the flexibility of the present formulation when attempting to characterize a large class of composite materials, and (2) its ability to predict anticipated qualitative trends in the fatigue behavior of unidirectional metal matrix composites. Additionally, the potential for the inclusion of various micromechanical effects (e.g., fiber/matrix bond strength, fiber volume fraction, etc.), into the phenomenological anisotropic parameters is noted, as well as a detailed discussion regarding the necessary exploratory and characterization experiments needed to utilize the featured damage theories. Arnold, S. M. and Kruch, S. Glenn Research Center...
Download or read book Differential Continuum Damage Mechanics Models for Creep and Fatigue of Unidirectional Metal Matrix Composites written by and published by . This book was released on 1991 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Creep Damage and Creep Fatigue Damage Interaction Model for Unidirectional Metal Matrix Composites written by S. Kruch and published by . This book was released on 1997 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: A multiaxial, isothermal, continuum damage mechanics model for creep and creep-fatigue interaction of a unidirectional metal-matrix composite (MMC) volume element is presented. The model is phenomenological, stress based, and assumes a single scalar internal damage variable with directional-dependent evolution. The present creep damage model is an extension of the Leckie-Hayhurst creep damage model to unidirectional MMCs and is shown when taken to its isotropic limit, to directly simplify to this previously developed and validated isotropic creep damage model. This extension is accomplished by introducing into the isochronous damage function physically meaningful stress invariants that reflect the local stress and material orientation within a metallic, transversely isotropic material (for example, hexagonally packed unidirectional metal-matrix composite). These invariants are included based on the anticipation that the associated stress may strongly influence void growth at the fiber-matrix interface (as this interface is postulated to play a role, on the mesostructural scale, analogous to that of grain boundaries on the microstructural scale and interfacial degradation); and, consequently may correlate with a creep rupture mechanism based on interfacial degradation through diffusion-related void growth.
Download or read book Applications of Continuum Damage Mechanics to Fatigue and Fracture written by David L. McDowell and published by ASTM International. This book was released on 1997 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contains papers from the May 1996 Symposium on Applications of Continuum Damage Mechanics (CDM) to Fatigue and Fracture. Papers in Section I deal with various aspects of modeling damage in composite materials, such as high temperature environmental degradation, fatigue, and viscous damage in metal a
Download or read book Advances in Damage Mechanics Metals and Metal Matrix Composites written by George Voyiadjis and published by Elsevier. This book was released on 2012-12-02 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides in a single and unified volume a clear and thorough presentation of the recent advances in continuum damage mechanics for metals and metal matrix composites. Emphasis is placed on the theoretical formulation of the different constitutive models in this area, but sections are added to demonstrate the applications of the theory. In addition, some sections contain new material that has not appeared before in the literature. The book is divided into three major parts: Part I deals with the scalar formulation and is limited to the analysis of isotropic damage in materials; Parts II and III deal with the tensor formulation and is applied to general states of deformation and damage. The material appearing in this text is limited to plastic deformation and damage in ductile materials (e.g. metals and metal matrix composites) but excludes many of the recent advances made in creep, brittle fracture, and temperature effects since the authors feel that these topics require a separate volume for this presentation. Furthermore, the applications presented in this book are the simplest possible ones and are mainly based on the uniaxial tension test.
Download or read book Continuum Damage Mechanics of Materials and Structures written by O. Allix and published by Elsevier. This book was released on 2002-08-13 with total page 397 pages. Available in PDF, EPUB and Kindle. Book excerpt: Created in 1975, LMT-Cachan is a joint laboratory École Normale Superieure de Cachan, Pierre & Marie Curie (Paris 6) University and the French Research Council CNRS (Department of Engineering Sciences). The Year 2000 marked the 25th anniversary of LMT. On this occasion, a series of lectures was organized in Cachan in September-October, 2000. This publication contains peer-reviewed proceedings of these lectures and is aimed to present engineers and scientists with an overview of the latest developments in the field of damage mechanics. The formulation of damage models and their identification procedures were discussed for a variety of materials.
Download or read book Creep written by Leo Razdolsky and published by CRC Press. This book was released on 2023-08-04 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, the application of composites and nanocomposites has been increasing steadily in industries such as aerospace, automotive, marine, and civil engineering. It is among the most complex and crucial aspects of the mechanics of a deformable solid, due to several specific phenomena and analytic factors arising from cyclic loading. The problems are primarily associated with the development of fatigue damage, and the need to assess the cyclic and structural instability of composite and nanocomposite materials. The study of structural strength under cyclic loading has gained much attention, especially in aircraft manufacturing, power engineering, aviation, and rocket technology. Cyclic loading significantly reduces creep-fatigue lifespan during the entire frequency range. It is clear that characteristics such as endurance limit, static creep limits and long-term static strength will not suffice in the design criteria for fatigue life. New aspects have emerged in high-temperature strength - cyclical creep and long-term cyclic strength, leading to the creation of new methods and means of determining the resistance of composites and nanocomposites materials and continuum damage development under cyclic loading to the creation of appropriate physical models. Particularly relevant is the intensification of creep by high-frequency cyclic loading in composite materials, which usually occurs at high temperatures. Most studies in the field of cyclic creep are experimental, and the direct use of number of cycles to define damage model cannot escape the empirical relation that predicts multi-stress level fatigue life well. The book presents new phenomenological cyclic creep – fatigue models for describing the fatigue life and behavior of time-dependent composites and nanocomposites. Since the main difference between the creep process from the fatigue process is that from a physical point of view, the first is quasi-static, and the second is dynamic. Therefore, the functions of creep should reflect the oscillatory nature of the fatigue process. The results are supported by step-by-step practical design examples and will be useful for practicing structural engineers, code developers as well as research and university faculty.
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 Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the ASME Aerospace and Materials Divisions written by Wen S. Chan and published by . This book was released on 1996 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contains papers from the November 1996 congress, reflecting recent research in failure mechanisms and mechanism-based modelling in high temperature composites, and durability and damage tolerance of composites.
Download or read book Contemporary Research in Engineering Science written by Romesh C. Batra and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue failures occur in aerospace,marine,nuclear structures and automobile com ponents from initiation and propagation of cracks from holes,scratches or defects in the material. To design against these failures, crack propagation life and fracture strength need to be accurately predicted. It is reported in the literature, that these failures often initiate as surface cracks, corner cracks and cracks emanating from fastner holes. Such cracks are with elliptic or nearly elliptic in shapes. The deviation from elliptic shape is due to varying constraint effect along the crack front. Even in situations, when the cracks are through the thickness of the material, there would be thicknesswise variation of constraint effects leading to three dimensional nature of crack growth. Accurate predictions of the crack growth in these cases by numerical methods can be made only by solving three-dimensional boundary value problems. Empirical relationships have been developed [1] based on Linear Elastic Fracture Mechanics over years describing fatigue crack growth response. Some of these empirical relationships required modifications in the later stages, to meet the design applications. The Crack closure phenomenon discovered by Elber[2, 3] during the crack growth phase is mainly attributed to the local material yielding near the crack tip and the consequent residual plastic wake behind the crack tip. It helped considerably in understanding several aspects of fatigue crack growth and rewrite these relations.
Download or read book A Coupled Uncoupled Computational Scheme for Deformation and Fatigue Damage Analysis of Unidirectional Metal Matrix Composites written by TE. Wilt and published by . This book was released on 1997 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: A fatigue damage computational algorithm utilizing a multiaxial, isothermal, continuum-based fatigue damage model for unidirectional metal-matrix composites has been implemented into the commercial finite element code MARC using MARC user subroutines. Damage is introduced into the finite element solution through the concept of effective stress that fully couples the fatigue damage calculations with the finite element deformation solution. Two applications using the fatigue damage algorithm are presented. First, an axisymmetric stress analysis of a circumferentially reinforced ring, wherein both the matrix cladding and the composite core were assumed to behave elastic-perfectly plastic. Second, a micromechanics analysis of a fiber/matrix unit cell using both the finite element method and the generalized method of cells (GMC). Results are presented in the form of S-N curves and damage distribution plots.
Download or read book Damage Mechanics of Composite Materials written by Klaus Friedrich and published by Elsevier Publishing Company. This book was released on 1994 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing a useful summary of current knowledge on the friction and wear properties of composite materials, this book fills the gap between publications on fundamental principles of tribology and those on the friction and wear behaviour of metals and polymers.
Download or read book MMC Life System Development phase I written by Erwin V. Zaretsky and published by . This book was released on 1996 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on with total page 846 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Composite Materials written by Charles E. Bakis and published by ASTM International. This book was released on 2003 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The 14th ASTM Symposium on Composite Materials: Testing and Design, was held March 11-12, 2002 in Pittsburgh, PA. The Testing and Design symposia, sponsored by Committee D30 on Composite Materials, have been scheduled on a roughly bi-yearly basis since 1969 to provide a forum for researchers and practitioners to meet and exchange their latest methods and findings related to the testing and design of composite materials and structures."
Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1992 with total page 982 pages. Available in PDF, EPUB and Kindle. Book excerpt:
