DYNAMIC PLASTICITY
2C#b-Y 1~N S y^et Copyright © 2007 by World Scientific Publishing Co. Pte. Ltd
yH]w(z5Z Xuj=V?5 The present book is not simply a new addition of the book Dynamic Plasticity,
j){0>O.V initially published in 1967, a long time ago. Certainly this edition is not only a new
.B{:<;sa version, containing the essential of the old book and what has been done meantime.
PKYm{wO- Why again Dynamic Plasticity? Well because very many books published meantime
U|v@v@IBA on the subject are not mentioning the waves which are to be considered in Dynamic
##'uekSJ Plasticity. Also, generally, the plastic waves are slower than the elastic one. Thus,
(VBO1 f when considering a simple problem of propagation of waves in thin bars, for any
a@m
64l) loading at the end, the plastic waves are reached by the elastic ones, and will not
IY}{ 1[<N propagate any more. Only a part of the bar is deforming plastically. Examples of
Zz! yv(e)H this kind are very few.
M7//*Q'? I thought that this new version is too restrictive for the today students which
,<U know little of static plasticity, differential equations, dynamic elastic–plastic properties,
&"c lBR Vg etc. Therefore, I thought to write a simpler book, containing the main
;9hS_%ldX4 concepts of dynamic plasticity, but also something else. Thus I thought that this
j4$NQ]e^4 new version would contain the elementary concepts of static plasticity, etc., which
*ch7z|wo. would be useful to give. Also it would be good to give other problems, not directly
>z k6{kC related to dynamic plasticity. Thus I started with some classical problems on
G@rV9 static plasticity, but only the simplest things, so that the readers would afterwards
wPaMYxO/ understand also the dynamic problems. Also, since in dynamic problems the soils
$|7;(2k and rocks played a fundamental role, I thought to write a chapter on rocks and soils.
DlQ*'PX7 Then were expressed several chapters about dynamic plasticity, as propagation of
eNr2-R elastic–plastic waves in thin bars, the rate influence and the propagation of waves
:xC1Ka%~ in flexible strings. It is good to remember here that all problems related to dynamic
SeBl*V problems, are to be considered using the mechanics of the wave propagation; without
T*](oA@ the wave propagation mechanics all results concerning constitutive equations,
rDC=rG rate effect, etc. are only informative. Such problems are mentioned however in the
7mnZ,gpb book. We have presented mainly the different aspects on constitutive equations of
>g2Z t;*@w materials, as resulting from dynamic problems. Rate effects are considered in this
#ib?6=sPC way. They have been used by a variety of authors. The same with the mechanics of
Q'0:k{G
flexible strings, presented afterwards. Not very many authors have considered till
ltOsl-OpR now the mechanics of deformable cables.
h&x;#.SYK Therefore I thought to write a very simple book, which can be read by the
*y N#q>1 students themselves, without any additional help. They can understand what
VF g"AJf “plasticity” is after all. Then several other problems have been presented. Not
D9\ E kX trying to remove the fundamentals, I have thought also to add some additional
3<}r+, j problems, which are in fact dynamic, though the inertia effect is disregarded. They
/m h # o are the stationary problems, quite often met in many applications. It is question
|] ]Rp obviously, about problems involving Bingham bodies, as wire drawing, floating with
;2'/rEq4o working plug, extrusion, stability of natural inclined plane, etc.
M)CQ|P Further I have considered various problems of plastic waves, using various
q6eD{/4a1 theories. Also the perforation problems, was presented, using various symmetry
K.42 VM)F assumptions, or any other assumption made.
;;mr?'R The last chapter is on hypervelocity impact. To keep it simple, I have given
[k60=$y only very few information about. Thus I wished to show what hypervelocity is and
pI}6AAs}Z how is it considered now.
Xe@:Aun Though the book is a very simple one, I wished to ask any author to disregard
WTwura, possible missing of some papers. All literature is certainly incomplete. One has
ab>>W!r@! done today much more than given here. It was impossible for me to mention “all”
M^0^l9 w authors in this field.
LNF|mS\+D N. D. Cristescu
q=;U(,Y cristesc@ufl.edu
