Download or read book The Initiation and Growth of Adiabatic Shear Bands written by T. W. Wright and published by . This book was released on 1985 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: A simple version of thermo/viscoplasticity theory is used to model the formation of adiabatic shear bands in high rate deformation of solids. The one dimensional shearing deformation of a finite slab is considered. For the constitutive assumptions made in this paper, homogeneous shearing produces a stress/strain response curve that always has a maximum when strain and rate hardening, plastic heating, and thermal softening are taken into account. Shear bands form if a perturbation is added to the homogeneous fields just before peak stress is obtained with these new fields being used as initial conditions. The resulting initial/boundary value problem is solved by the finite element method for one set of material parameters. The shear band grows slowly at first, then accelerates sharply, until finally the plastic strain rate in the center reaches a maximum, followed by a slow decline. Stress drops rapidly throughout the slab, and the central temperature increases rapidly as the peak in strain rate develops.

Download or read book Further Results on the Initiation and Growth of Adiabatic Shear Bands written by Thomas W. Wright and published by . This book was released on 1986 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Growth of perturbations in the simple shearing deformation of a softening thermo-visco-plastic solid have been examined by means of a finite element technique. It has been found that very small perturbations grow slowly at first, even though the underlying homogeneous stress strain response has passed peak stress, but that eventually explosive growth occurs. During the slow growth phase, the stress follows the homogeneous response quite closely, but in the explosive phase, the stress drops precipitously. Large perturbations grow at a larger initial rate, and accelerate rapildy even before peak homogeneous stress. Inclusion of a dipolar plastic effect appears to be stabilizing. Keywords: Plastic deformation; Material instability; and Adiabatic shear bands.

Download or read book The Initiation and Growth of Shear Bands written by J. R. Rice and published by . This book was released on 1973 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Prior Quasistatic Loading Defect Shape and Defect Size on the Initiation and Growth of Dynamic Adiabatic Shear Bands written by Chandramohan Reddy Adulla and published by . This book was released on 1994 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Consideration of Microstructural Changes in the Study of Adiabatic Shear Bands written by and published by . This book was released on 1994 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have analyzed the effect of microstructural changes on the initiation and growth of shear bands. These have been studied by developing an adaptive mesh refinement technique to decipher adiabatic shear bands in two-dimensional problems, formulating a three-dimensional finite-deformation theory for dipolar thermoviscoplastic materials and using it to examine the initiation and growth of shear bands in plane strain thermomechanical deformations of dipolar materials, employing an internal variable theory of Brown, Kim and Anand to study the shear band problem, investigating the possibility of phase transformations during the development of adiabatic shear bands in a steel specimen, ascertaining the speed of propagation of a shear band in a steel tube, assessing the effect of frictional forces between the loading device and the cylinder ends, and, analyzing the development of a shear band in a FCC single crystal. Principal results obtained during these investigations are summarized in the report. (AN).

Download or read book Some Aspects of Adiabatic Shear Bands written by Thomas W. Wright and published by . This book was released on 1987 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: A one-dimensional continuum formulation for the initiation and growth of adiabatic shear bands is reviewed, including some remarks on the underlying assumptions. A short description of some perturbation calculations introduces the idea of stress collapse and band formation as a bifurcation from homogeneous deformation, and an approach for estimating the critical time of collapse for infinitesimal perturbations is introduced. Steady solutions are exhibited and their interpretation as central boundary layers is suggested. Finally it is shown that in a certain limit shear bands occur following a hyperbolic to elliptic transition in the governing equation, and in a concluding remark dipolar plasticity is introduced as a possible alternative continuum description.

Download or read book Adiabatic Shear Localization written by Bradley Dodd and published by Elsevier. This book was released on 2012-05-22 with total page 469 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rev. ed. of: Adiabatic shear localization / Y. Bai and B. Dodd. 1992. 1st ed.

Download or read book Analysis of Adiabatic Shear Bands in Thermoviscoplastic Materials Under Combined Loading written by and published by . This book was released on 1994 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: We study the initiation and growth of adiabatic shear bands in a thin-walled steel tube deformed first quasistatically either in simple compression or simple tension or by a pressure applied to the inner surface of the tube and then one end of the tube is kept fixed and the other end is twisted with a prescribed tangential speed. The objective is to see how prior quasistatic deformations of the tube affect the nominal shear strain at which a shear band initiates in the tube. The first set of numerical experiments simulates tests recently conducted by Murphy who found that the nominal strain at the initiation of the shear bands decreased with an increase in the axial static compressive stress induced in the tube. (AN).

Download or read book The Physics and Mathematics of Adiabatic Shear Bands written by T. W. Wright and published by Cambridge University Press. This book was released on 2002-07-22 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a research monograph on the material instability known as adiabatic shear banding which often occurs in a plastically deforming material as it undergoes rapid shearing. Plastic deformation generates heat, which eventually softens most materials with continued straining, a process which is usually unstable. In this case the instability results in thin regions of highly deformed material, which are often the sites of further damage and complete failure. The main body of the book examines a series of one-dimensional problems of increasing complexity. In this way a comprehensive and quantitative picture of the complete phenomena is built up. Particular care is taken to use well established asymptotic techniques to find simple, but universal, analytic expressions or scaling laws that encapsulate various aspects of the dynamic formation and the final morphology of shear bands. A fully developed mechanics of shear is just beginning to emerge as a major companion to fracture mechanics, this book may speed the process along.

Download or read book Initiation of Adiabatic Shear Bands from a Microstructural Standpoint written by Doctor Shmuel Osovski and published by . This book was released on 2013 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On Stress Collapse in Adiabatic Shear Bands written by Thomas W. Wright and published by . This book was released on 1987 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dynamics of adiabatic shear band formation is considered making use of a simplified thermo/visco/plastic flow law. A new numerical solution is used to follow the growth of a perturbation from initiation, through early growth and severe localization, to a slowly varying terminal configuration. Asymptotic analyses predict the early and late stage patterns, but the timing and structure of the abrupt transition to severe localization can only be studied numerically, to date. A characteristic feature of the process is that temperature and plastic strain rate begin to localize immediately, but only slowly, whereas the stress first evolves almost as if there were no perturbation, but then collapses rapidly when severe localization occurs.

Download or read book Adiabatic Shear Bands in Simple and Dipolar Plastic Materials written by Thomas W. Wright and published by . This book was released on 1987 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Introduction To Adiabatic Shear Localization Revised Edition written by Bradley Dodd and published by World Scientific Publishing Company. This book was released on 2014-08-14 with total page 469 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adiabatic shear bands are found in a variety of metals and other materials; they cause rapid weakening due to energy concentration into narrow regions of the material. This is the very first book on this important topic and the only true introduction to the subject. An enhanced and updated student-friendly edition of the authors' 1992 book Adiabatic Shear Localization: Occurrence, Theories and Applications, this seminal text now includes essential Further Reading sections in some chapters. It explains adiabatic shear bands in a descriptive rather than a mathematical way, with a ‘quick reference’ section for readers wanting a more rapid introduction. Entirely comprehensive, the reader can dip into the chapters as suits his or her course material or research.If you are a postgraduate materials scientist, engineer, physicist, metallurgist, or indeed any researcher in materials that undergo rapid deformation and failure, this text is not to be missed.

Download or read book Macro and Micro Mechanics of High Velocity Deformation and Fracture written by Kozo Kawata and published by Springer. This book was released on 2011-12-22 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The IUTAM Symposium on Macro- and Micro-Mechanics of High Velocity Deformation and Fracture (MMMHVDF) (August 12 - 15, 1985) was held at Science Council of Japan, under the sponsor ship of IUTAM, Science Council of Japan, Japan Society for the Promotion of Science, The Commemorative Association for the Japan World Exposition (1970), and The Japan Society for Aeronautical and Space Sciences. The proposal of the symposium was accepted by the General Assembly of IUTAM, and the scientists mentioned below were appointed by the Bureau of IUTAM to serve as member of the Scientific Committee. The main object of the Symposium was to make a general survey of recent developments in the re search of high velocity solid mechanics and to explore further new ideas for dealing with unsettled problems, of fundamental nature as well as of practical importance. The subjects covered theoretical, experimental, and numerical fields in macro- and micro-mechanics associated with high velocity de formatio~ and fracture in soldis, covering metals, ceramics, polymers, and composites.

Download or read book Dynamic Damage and Fragmentation written by David Edward Lambert and published by John Wiley & Sons. This book was released on 2019-01-14 with total page 439 pages. Available in PDF, EPUB and Kindle. Book excerpt: Engineering structures may be subjected to extreme high-rate loading conditions, like those associated with natural disasters (earthquakes, tsunamis, rock falls, etc.) or those of anthropic origin (impacts, fluid–structure interactions, shock wave transmissions, etc.). Characterization and modeling of the mechanical behavior of materials under these environments is important in predicting the response of structures and improving designs. This book gathers contributions by eminent researchers in academia and government research laboratories on the latest advances in the understanding of the dynamic process of damage, cracking and fragmentation. It allows the reader to develop an understanding of the key features of the dynamic mechanical behavior of brittle (e.g. granular and cementitious), heterogeneous (e.g. energetic) and ductile (e.g. metallic) materials.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1987 with total page 948 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Adiabatic Shear Band Formation in Titanium written by M. Laxmi Prasad and published by . This book was released on 1993 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: