DYNAMIC PLASTICITY
^':A z6Z u>~G)lx% Copyright © 2007 by World Scientific Publishing Co. Pte. Ltd
&FQ]`g3_@ GJ >vL The present book is not simply a new addition of the book Dynamic Plasticity,
bLx70$ initially published in 1967, a long time ago. Certainly this edition is not only a new
HJY_l version, containing the essential of the old book and what has been done meantime.
@!92Ok Why again Dynamic Plasticity? Well because very many books published meantime
:#M(,S"Qq on the subject are not mentioning the waves which are to be considered in Dynamic
{.W$<y (j7 Plasticity. Also, generally, the plastic waves are slower than the elastic one. Thus,
<h_ lc}o/ when considering a simple problem of propagation of waves in thin bars, for any
O*af`J{ loading at the end, the plastic waves are reached by the elastic ones, and will not
fo"dX4%} propagate any more. Only a part of the bar is deforming plastically. Examples of
4KB) UPW this kind are very few.
yFt'<{z[nL I thought that this new version is too restrictive for the today students which
b";w\H know little of static plasticity, differential equations, dynamic elastic–plastic properties,
O/gBBTB etc. Therefore, I thought to write a simpler book, containing the main
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a concepts of dynamic plasticity, but also something else. Thus I thought that this
{FR#je new version would contain the elementary concepts of static plasticity, etc., which
$qN+BKd]3 would be useful to give. Also it would be good to give other problems, not directly
AHws5#;$6* related to dynamic plasticity. Thus I started with some classical problems on
1goK>=-^ static plasticity, but only the simplest things, so that the readers would afterwards
@@U'I ^iG understand also the dynamic problems. Also, since in dynamic problems the soils
3r=IO# and rocks played a fundamental role, I thought to write a chapter on rocks and soils.
%@<}z|.4 Then were expressed several chapters about dynamic plasticity, as propagation of
oa:GGW4Q elastic–plastic waves in thin bars, the rate influence and the propagation of waves
5S PGv}if in flexible strings. It is good to remember here that all problems related to dynamic
C 9-90,
problems, are to be considered using the mechanics of the wave propagation; without
buGYHZu the wave propagation mechanics all results concerning constitutive equations,
[CH%(#>i~ rate effect, etc. are only informative. Such problems are mentioned however in the
MSPzOJQPy book. We have presented mainly the different aspects on constitutive equations of
_7SOl. 5ZE materials, as resulting from dynamic problems. Rate effects are considered in this
=,D3e+ P' way. They have been used by a variety of authors. The same with the mechanics of
T-=sC =sS, flexible strings, presented afterwards. Not very many authors have considered till
xUYUO yV now the mechanics of deformable cables.
P |c6V Therefore I thought to write a very simple book, which can be read by the
f-5vE9G3y7 students themselves, without any additional help. They can understand what
e_6@oh2s- “plasticity” is after all. Then several other problems have been presented. Not
w hW"c Fg trying to remove the fundamentals, I have thought also to add some additional
Ctbm X)vE problems, which are in fact dynamic, though the inertia effect is disregarded. They
saOXbt (& are the stationary problems, quite often met in many applications. It is question
?YY'-\h? obviously, about problems involving Bingham bodies, as wire drawing, floating with
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M2|-C working plug, extrusion, stability of natural inclined plane, etc.
u</21fz' Further I have considered various problems of plastic waves, using various
uS3 s theories. Also the perforation problems, was presented, using various symmetry
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assumptions, or any other assumption made.
xz dq E The last chapter is on hypervelocity impact. To keep it simple, I have given
=K# D^c~ only very few information about. Thus I wished to show what hypervelocity is and
#UH|,>W6 how is it considered now.
qyMR0ai- Though the book is a very simple one, I wished to ask any author to disregard
kV7c\|N9 possible missing of some papers. All literature is certainly incomplete. One has
g/+P]c6/ done today much more than given here. It was impossible for me to mention “all”
#!\g5 ')mC authors in this field.
;o;P2}zD N. D. Cristescu
XW6>;:4k cristesc@ufl.edu
