New contributions to the cyclic plasticity of engineering materials Written by leading experts in the field, this book provides an authoritative and comprehensive introduction to cyclic plasticity of metals, polymers, composites and shape memory alloys. Each chapter is devoted to fundamentals of cyclic plasticity or to one of the major classes of materials, thereby providing a wide coverage of the field. The book deals with experimental observations on metals, composites, polymers and shape memory alloys, and the corresponding cyclic plasticity models for metals, polymers, particle reinforced metal matrix composites and shape memory alloys. Also, the thermo-mechanical coupled cyclic plasticity models are discussed for metals and shape memory alloys. Key features: Provides a comprehensive introduction to cyclic plasticity Presents Macroscopic and microscopic observations on the ratchetting of different materials Establishes cyclic plasticity constitutive models for different materials. Analysis of cyclic plasticity in engineering structures. This book is an important reference for students, practicing engineers and researchers who study cyclic plasticity in the areas of mechanical, civil, nuclear, and aerospace engineering as well as materials science.
|Author||: Jaroslav Polák|
|Release Date||: 1991|
|ISBN 10||: 9780444416858|
|Pages||: 315 pages|
Constitutive modelling is the mathematical description of how materials respond to various loadings. This is the most intensely researched field within solid mechanics because of its complexity and the importance of accurate constitutive models for practical engineering problems. Topics covered include: Elasticity - Plasticity theory - Creep theory - The nonlinear finite element method - Solution of nonlinear equilibrium equations - Integration of elastoplastic constitutive equations - The thermodynamic framework for constitutive modelling – Thermoplasticity - Uniqueness and discontinuous bifurcations • More comprehensive in scope than competitive titles, with detailed discussion of thermodynamics and numerical methods. • Offers appropriate strategies for numerical solution, illustrated by discussion of specific models. • Demonstrates each topic in a complete and self-contained framework, with extensive referencing.
In several industrial fields (such as automotive, steelmaking, aerospace, and fire protection systems) metals need to withstand a combination of cyclic loadings and high temperatures. In this condition, they usually exhibit an amount—more or less pronounced—of plastic deformation, often accompanied by creep or stress-relaxation phenomena. Plastic deformation under the action of cyclic loadings may cause fatigue cracks to appear, eventually leading to failures after a few cycles. In estimating the material strength under such loading conditions, the high-temperature material behavior needs to be considered against cyclic loading and creep, the experimental strength to isothermal/non-isothermal cyclic loadings and, not least of all, the choice and experimental calibration of numerical material models and the selection of the most comprehensive design approach. This book is a series of recent scientific contributions addressing several topics in the field of experimental characterization and physical-based modeling of material behavior and design methods against high-temperature loadings, with emphasis on the correlation between microstructure and strength. Several material types are considered, from stainless steel, aluminum alloys, Ni-based superalloys, spheroidal graphite iron, and copper alloys. The quality of scientific contributions in this book can assist scholars and scientists with their research in the field of metal plasticity, creep, and low-cycle fatigue.
|Author||: Joël Lépinoux,Dominique Mazière,Vassilis Pontikis,Georges Saada|
|Publisher||: Springer Science & Business Media|
|Release Date||: 2012-12-06|
|ISBN 10||: 9401140480|
|Pages||: 529 pages|
A profusion of research and results on the mechanical behaviour of crystalline solids has followed the discovery of dislocations in the early thirties. This trend has been enhanced by the development of powerful experimental techniques. particularly X ray diffraction. transmission and scanning electron microscopy. microanalysis. The technological advancement has given rise to the study of various and complex materials. not to speak of those recently invented. whose mechanical properties need to be mastered. either for their lise as structural materials. or more simply for detenllining their fonnability processes. As is often the case this fast growth has been diverted both by the burial of early fundamental results which are rediscovered more or less accurately. and by the too fast publication of inaccurate results. which propagate widely. and are accepted without criticism. Examples of these statements abound. and will not be quoted here for the sake of dispassionateness. Understanding the mechanical properties of materials implies the use of various experimental techniques. combined with a good theoretical knowledge of elasticity. thermodynamics and solid state physics. The recent development of various computer techniques (simulation. ab initio calculations) has added to the difficulty of gathering the experimental information. and mastering the theoretical understanding. No laboratory is equipped with all the possible experimental settings. almost no scientist masters all this theoretical kno\vledge. Therefore. cooperation between scientists is needed more than even before.
|Author||: Abdullah Aziz Saad|
|Release Date||: 2012|
|Pages||: 329 pages|
The thermo-mechanical fatigue (TMF) of power plant components is caused by the cyclic operation of power plant due to startup and shutdown processes and due to the fluctuation of demand in daily operation. Thus, a time-dependent plasticity model is required in order to simulate the component response under cyclic thermo-mechanical loading. The overall aim behind this study is to develop a material constitutive model, which can predict the creep and cyclic loading behaviour at high temperature environment, based on the cyclic loading test data of the P91 and the P92 steels. The tests on all specimens in the study were performed using the Instron 8862 TMF machine system with a temperature uniformity of less than ±10°C within the gauge section of the specimen. For the isothermal tests on the P91 steel, fully-reversed, strain-controlled tests were conducted on a parent material of the steel at 400, 500 and 600 ̊C. For the P92 steel, the same loading parameters in the isothermal tests were performed on a parent material and a weld metal of the steels at 500, 600 and 675°C. Strain-controlled thermo-mechanical fatigue tests were conducted on the parent materials of the P91 and the P92 steels under temperature ranges of 400-600°C and 500-675°C, respectively, with in-phase (IP) and out-of-phase (OP) loading. In general, the steels exhibit cyclic softening behaviour throughout the cyclic test duration under both isothermal and anisothermal conditions. The cyclic softening behaviour of the P91 steel was further studied by analyzing stress-strain data at 600°C and by performing microstructural investigations. Scanning electron microscope (SEM) and transmission electron microscope (TEM) images were used to investigate microstructural evolution and the crack initiation of the steel at different life fractions of the tests. The TEM images of the interrupted test specimens revealed subgrain coarsening during the cyclic tests. On the other hand, the SEM images showed the initiation of microcracks at the end of the stabilisation period and the cracks were propagated in the third stage of cyclic softening. A unified, Chaboche, viscoplasticity model, which includes combined isotropic softening and kinematic hardening with a viscoplastic flow rule for time-dependent effects, was used to model the TMF behaviour of the steels The constants in the viscoplasticity model were initially determined from the first cycle stress-strain data, the maximum stress evolution during tests and the stress relaxation data. Then, the initial constants were optimized using a least-squares optimization algorithm in order to improve the general fit of the model to experimental data. The prediction of the model was further improved by including the linear nonlinear isotropic hardening in order to obtain better stress-strain behaviour in the stabilisation period. The developed viscoplasticity model was subsequently used in the finite element simulations using the ABAQUS software. The focus of the simulation is to validate the performance of the model under various types of loading. Simulation results have been compared with the isothermal test data with different strain ranges and also the anisothermal cyclic testing data, for both in-phase and out-of-phase loadings. The model's performance under 3-dimensional stress conditions was investigated by testing and simulating the P91 steel using a notched specimen under stress-controlled conditions. The simulation results show a good comparison to the experimental data.
Fracture mechanics is an essential tool for engineers in a number of different engineering disciplines. For example, an engineer in a metals- or plastics-dependent industry might use fracture mechanics to evaluate and characterize materials, while another in aerospace or construction might use fracture mechanics-based methods for product design and service life-time estimation. This balanced treatment, which covers both applied engineering and mathematical aspects of the topic, provides a much-needed multidisciplinary treatment of the field suitable for the many diverse applications of the subject. While texts on linear elastic fracture mechanics abound, no complete treatments of the complex topic of nonlinear fracture mechanics have been available in a textbook format - until now. Written by an author with extensive industry credentials as well as academic experience, Nonlinear Fracture Mechanics for Engineers examines nonlinear fracture mechanics and its applications in mechanics, materials testing, and life prediction of components. The book includes the first-ever complete examination of creep and creep-fatigue crack growth. Examples and problems reinforce the concepts presented. A complete chapter on applications and case studies involving nonlinear fracture mechanics completes this thorough evaluation of this dynamic field of study.
|Author||: Deutsche Forschungsgemeinschaft|
|Release Date||: 2001|
|Pages||: 398 pages|
This is the final report, drawing its conclusions and results from many individual papers and co-workers at the Institute for Structural Analysis of the Technical University of Braunschweig. It shows the correlation between energetic and mechanical quantities of face-centred cubic metals, cold worked and softened to different states. Constitutive models for the plastic of metals are developed and the application of these models is presented. The improvements achieved by this contribution cover the material functions, the shape of yield surfaces, and the consideration of distributed experimental data within the mumerical analysis.
|Author||: Fusahito Yoshida,Hiroshi Hamasaki|
|Publisher||: Trans Tech Publications Ltd|
|Release Date||: 2016-12-15|
|ISBN 10||: 3035730245|
|Pages||: 736 pages|
Selected, peer reviewed papers from the 13th Asia-Pacific Symposium on Engineering Plasticity and its Applications (AEPA2016), December 4-8, 2016, Hiroshima, Japan
An integral review is given in this book on the fatigue phenomenon covering the fundamentals of fatigue damage initiation, relevant factors influencing fatigue crack propagation and fatigue life, random load analysis, and simulation for theoretical and experimental fatigue life assessment. The entire chain of problems related to fatigue of metals and structural components is covered. Specifically, it describes the low-cycle plastic properties and statistically interprets the material stress reaction, examining original results of investigations on inelastic deformations under high cycle cyclic loading and correlating them with a number of use parameters. The limit states of bodies with primary defects and their resistance to fatigue crack propagation are discussed. Measurements, analysis and real-time modelling of operating loads for experimental fatigue life verification are reviewed as well as introducing some new fatigue damage accumulation hypotheses based on dissipated energy.
This book serves both as a textbook and a scientific work. As a textbook, the work gives a clear, thorough and systematic presentation of the fundamental postulates, theorems and principles and their applications of the classical mathematical theories of plasticity and creep. In addition to the mathematical theories, the physical theory of plasticity, the book presents the Budiansky concept of slip and its modification by M. Leonov. Special attention is given to the analysis of the advantages and shortcomings of the classical theories. In its main part, the book presents the synthetic theory of irreversible deformations, which is based on the mathematical Sanders flow plasticity theory and the physical theory, the Budiansky concept of slip. The main peculiarity of the synthetic theory is that the formulae for both plastic and creep deformation, as well their interrelations, can be derived from the single constitutive equation. Furthermore, the synthetic theory, as physical one, can take into account the real processes that take place in solids at irreversible deformation. This widens considerably the potential of the synthetic theory. In the framework of the synthetic theory such problems as creep delay, the Hazen-Kelly effect, the deformation at the break of the load trajectory, the influence of the rate of loading on the stress-strain diagram, creep at the changes of load, creep at unloading and reversed creep, have been analytically described. In the last chapter, the book shows the solution of some contemporary problems of plasticity and creep: Creep deformation at cyclic abrupt changes of temperature, The influence of irradiation on the plastic and creep deformation, Peculiarities of deformation at the phase transformation of some metals.
|Release Date||: 2012|
|Pages||: 329 pages|
Plate impact experiments with pressures from 2 to 20 GPa, including one shock-partial release-reshock experiment, were performed on vacuum hot-pressed S-200F Beryllium. This hexagonal close-packed (HCP) metal shows significant plasticity effects in such conditions. The experiments were modeled in a Lagrangian hydrocode using an experimentally calibrated Preston-Tonks-Wallace (PTW) constitutive model. By using the shock data to constrain a high rate portion of PTW, the model was able to generally match plasticity effects on the measured wave profile (surface velocity) during the shock loading, but not unloading. A backstress-based cyclic plasticity model to capture the quasi-elastic release (Bauschinger-type effect) was explored in order to match the unloading and reloading portions of the measured wave profiles. A comparison is made with other approaches in the literature to capture the cyclic plasticity in shock conditions.
|Author||: A.K. Miller|
|Publisher||: Springer Science & Business Media|
|Release Date||: 2012-12-06|
|ISBN 10||: 9400934394|
|Pages||: 342 pages|
Constitutive equations refer to 'the equations that constitute the material response' at any point within an object. They are one of the ingredients necessary to predict the deformation and fracture response of solid bodies (among other ingredients such as the equations of equilibrium and compatibility and mathematical descriptions of the configuration and loading history). These ingredients are generally combined together in complicated computer programs, such as finite element analyses, which serve to both codify the pertinent knowledge and to provide convenient tools for making predictions of peak stresses, plastic strain ranges, crack growth rates, and other quantities of interest. Such predictions fall largely into two classes: structural analysis and manufacturing analysis. In the first category, the usual purpose is life prediction, for assessment of safety, reliability, durability, and/or operational strategies. Some high-technology systems limited by mechanical behavior, and therefore requiring accurate life assess ments, include rocket engines (the space-shuttle main engine being a prominent example), piping and pressure vessels in nuclear and non-nuclear power plants (for example, heat exchanger tubes in solar central receivers and reformer tubes in high-temperature gas-cooled reactors used for process heat applications), and the ubiquitous example of the jet engine turbine blade. In structural analysis, one is sometimes concerned with predicting distortion per se, but more often, one is concerned with predicting fracture; in these cases the informa tion about deformation is an intermediate result en route to the final goal of a life prediction.
Contents Recent advancements in the performance of industrial products and structures are quite intense. Consequently, mechanical design of high accuracy is necessary to enhance their mechanical performance, strength and durability. The basis for their mechanical design can be provided through elastoplastic deformation analyses. For that reason, industrial engineers in the fields of mechanical, civil, architec- ral, aerospace engineering, etc. must learn pertinent knowledge relevant to elas- plasticity. Numerous books about elastoplasticity have been published since “Mathema- cal Theory of Plasticity”, the notable book of R. Hill (1950), was written in the middle of the last century. That and similar books mainly address conventional plasticity models on the premise that the interior of a yield surface is an elastic domain. However, conventional plasticity models are applicable to the prediction of monotonic loading behavior, but are inapplicable to prediction of deformation behavior of machinery subjected to cyclic loading and civil or architectural str- tures subjected to earthquakes. Elastoplasticity has developed to predict defor- tion behavior under cyclic loading and non-proportional loading and to describe nonlocal, finite and rate-dependent deformation behavior.
|Author||: P.D. Portella,K.-T. Rie|
|Release Date||: 1998-09-30|
|ISBN 10||: 9780080549941|
|Pages||: 890 pages|
The 4th International Conference on Low Cycle Fatigue and Elasto-Plastic Behaviour of Materials was held from 7-11 September 1998 in Garmisch-Partenkirchen, Germany. In response to a call for papers, nearly 200 extended abstracts from 32 countries were submitted to the organizing committee. These papers were presented at the conference as invited lectures or short contributions and as oral or poster presentation. All the papers were presented in poster form in extended poster sessions–a peculiarity of the LCF Conferences which allows an intense, thorough discussion of all contributions. Each chapter provides a comprehensive overview of a materials class or a given subject. Many contributions could have been included in two or even three chapters and so, in order to give a better overview of the content, the reader will find a subject index, a material index and an author index in the back of the book.
|Author||: T. Abe,T. Tsuruta|
|Release Date||: 2012-12-02|
|ISBN 10||: 0080984568|
|Pages||: 938 pages|
AEPA '96 provides a forum for discussion on the state-of-art developments in plasticity. An emphasis is placed on the close interaction of the theories from macroplasticity, mesoplasticity and microplasticity together with their applications in various engineering disciplines such as solid mechanics, metal forming, structural analysis, geo-mechanics and micromechanics. These proceedings include over 140 papers from the conference including case studies showing applications of plasticity in inter-disciplinary or nonconventional areas.
Written by the leading experts in computational materials science, this handy reference concisely reviews the most important aspects of plasticity modeling: constitutive laws, phase transformations, texture methods, continuum approaches and damage mechanisms. As a result, it provides the knowledge needed to avoid failures in critical systems udner mechanical load. With its various application examples to micro- and macrostructure mechanics, this is an invaluable resource for mechanical engineers as well as for researchers wanting to improve on this method and extend its outreach.