DYNAMIC PLASTICITY
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F+Bt` R^6]v`j; Copyright © 2007 by World Scientific Publishing Co. Pte. Ltd
xf3;:soC byHXRA)39 The present book is not simply a new addition of the book Dynamic Plasticity,
zP>=K initially published in 1967, a long time ago. Certainly this edition is not only a new
04c`7[ version, containing the essential of the old book and what has been done meantime.
kS62]v] Why again Dynamic Plasticity? Well because very many books published meantime
2m,t<Y; on the subject are not mentioning the waves which are to be considered in Dynamic
$Yj4&Two< Plasticity. Also, generally, the plastic waves are slower than the elastic one. Thus,
^f ] 9^U{ when considering a simple problem of propagation of waves in thin bars, for any
UYH&x:WEd loading at the end, the plastic waves are reached by the elastic ones, and will not
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}5Dc,eR propagate any more. Only a part of the bar is deforming plastically. Examples of
OzV|z/R2' this kind are very few.
N&G; ` I thought that this new version is too restrictive for the today students which
eB_ M *+^ know little of static plasticity, differential equations, dynamic elastic–plastic properties,
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Ml etc. Therefore, I thought to write a simpler book, containing the main
" y-/ 9C concepts of dynamic plasticity, but also something else. Thus I thought that this
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new version would contain the elementary concepts of static plasticity, etc., which
vMYEP_lhK, would be useful to give. Also it would be good to give other problems, not directly
a?X #G/) related to dynamic plasticity. Thus I started with some classical problems on
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v 4 static plasticity, but only the simplest things, so that the readers would afterwards
;y.<I& understand also the dynamic problems. Also, since in dynamic problems the soils
08z?i and rocks played a fundamental role, I thought to write a chapter on rocks and soils.
}LwKi-G? Then were expressed several chapters about dynamic plasticity, as propagation of
r12 e26_Ab elastic–plastic waves in thin bars, the rate influence and the propagation of waves
@<$_X1)s in flexible strings. It is good to remember here that all problems related to dynamic
5XZ\7Z| problems, are to be considered using the mechanics of the wave propagation; without
^o(C\\>{& the wave propagation mechanics all results concerning constitutive equations,
ub-vtRpm rate effect, etc. are only informative. Such problems are mentioned however in the
Vr KFpFd book. We have presented mainly the different aspects on constitutive equations of
l (3\ek U! materials, as resulting from dynamic problems. Rate effects are considered in this
Lf+3 nN way. They have been used by a variety of authors. The same with the mechanics of
'ALe>\WO flexible strings, presented afterwards. Not very many authors have considered till
Wdp4'rB now the mechanics of deformable cables.
`aM8L Therefore I thought to write a very simple book, which can be read by the
| DUOy Q students themselves, without any additional help. They can understand what
oF.H?lG7` “plasticity” is after all. Then several other problems have been presented. Not
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trying to remove the fundamentals, I have thought also to add some additional
Fv3:J~Yf problems, which are in fact dynamic, though the inertia effect is disregarded. They
sf,9Ym are the stationary problems, quite often met in many applications. It is question
cJ#%OU3 p obviously, about problems involving Bingham bodies, as wire drawing, floating with
+IM6 GeH working plug, extrusion, stability of natural inclined plane, etc.
w V"C ,*V Further I have considered various problems of plastic waves, using various
oN[# C>#( theories. Also the perforation problems, was presented, using various symmetry
:Oc&{z?q assumptions, or any other assumption made.
(*G'~gSX The last chapter is on hypervelocity impact. To keep it simple, I have given
eB5<N?;s only very few information about. Thus I wished to show what hypervelocity is and
E#`JH how is it considered now.
*cc|(EM Though the book is a very simple one, I wished to ask any author to disregard
g?9%_&/})A possible missing of some papers. All literature is certainly incomplete. One has
M7 gM#bv>L done today much more than given here. It was impossible for me to mention “all”
W4S]2P>T authors in this field.
^ " 4u1 N. D. Cristescu
@, SN8K0T cristesc@ufl.edu
