DYNAMIC PLASTICITY
Vmb `%k20' '*d);{D8 Copyright © 2007 by World Scientific Publishing Co. Pte. Ltd
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N$soaUs L2WH-XP= The present book is not simply a new addition of the book Dynamic Plasticity,
;*AK eI2 initially published in 1967, a long time ago. Certainly this edition is not only a new
cy%S 5Rz version, containing the essential of the old book and what has been done meantime.
,x] xt g? Why again Dynamic Plasticity? Well because very many books published meantime
sfUKH;xC on the subject are not mentioning the waves which are to be considered in Dynamic
==^9_a^ Plasticity. Also, generally, the plastic waves are slower than the elastic one. Thus,
`9>1 w d when considering a simple problem of propagation of waves in thin bars, for any
FV o_=O) loading at the end, the plastic waves are reached by the elastic ones, and will not
o)U4RY* propagate any more. Only a part of the bar is deforming plastically. Examples of
$p?TE 8G this kind are very few.
,bU 8S \8 I thought that this new version is too restrictive for the today students which
wVMR&R <t know little of static plasticity, differential equations, dynamic elastic–plastic properties,
YB?5s`vr9d etc. Therefore, I thought to write a simpler book, containing the main
),%(A~\ concepts of dynamic plasticity, but also something else. Thus I thought that this
id=:J7!QU new version would contain the elementary concepts of static plasticity, etc., which
pI]tv@ >:f would be useful to give. Also it would be good to give other problems, not directly
5;4bZ3e,0 related to dynamic plasticity. Thus I started with some classical problems on
fEgwQ-] static plasticity, but only the simplest things, so that the readers would afterwards
8~6 H\.0Q understand also the dynamic problems. Also, since in dynamic problems the soils
C\RJ){dk and rocks played a fundamental role, I thought to write a chapter on rocks and soils.
.^ o3 Then were expressed several chapters about dynamic plasticity, as propagation of
]$=\zL elastic–plastic waves in thin bars, the rate influence and the propagation of waves
Yg< 4}l." in flexible strings. It is good to remember here that all problems related to dynamic
gOSFvH8FU problems, are to be considered using the mechanics of the wave propagation; without
?V9Da;cj the wave propagation mechanics all results concerning constitutive equations,
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rate effect, etc. are only informative. Such problems are mentioned however in the
iQ7S*s+l5O book. We have presented mainly the different aspects on constitutive equations of
na) -' materials, as resulting from dynamic problems. Rate effects are considered in this
<,\Op=$l3I way. They have been used by a variety of authors. The same with the mechanics of
J =j6rD flexible strings, presented afterwards. Not very many authors have considered till
{OBV+}# now the mechanics of deformable cables.
~Ih LjE Therefore I thought to write a very simple book, which can be read by the
M7x*LiKc2 students themselves, without any additional help. They can understand what
mcgkNED “plasticity” is after all. Then several other problems have been presented. Not
9% wVE] trying to remove the fundamentals, I have thought also to add some additional
f?[0I\V[$ problems, which are in fact dynamic, though the inertia effect is disregarded. They
@ 5tW*:s are the stationary problems, quite often met in many applications. It is question
dF#`_!4pbf obviously, about problems involving Bingham bodies, as wire drawing, floating with
4eh~/o&h working plug, extrusion, stability of natural inclined plane, etc.
i7#PYt Further I have considered various problems of plastic waves, using various
_f1~r^(/T0 theories. Also the perforation problems, was presented, using various symmetry
R{R'byre assumptions, or any other assumption made.
;+6TZqklQ The last chapter is on hypervelocity impact. To keep it simple, I have given
%k8 H'w\ only very few information about. Thus I wished to show what hypervelocity is and
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S% how is it considered now.
|9& bkojo Though the book is a very simple one, I wished to ask any author to disregard
O_bgrX g6x possible missing of some papers. All literature is certainly incomplete. One has
|tVWmm^m done today much more than given here. It was impossible for me to mention “all”
A6faRi703 authors in this field.
:u4q.^&!e N. D. Cristescu
6&qT1nF1
cristesc@ufl.edu
