Plasticity - Mathematical Theory and Numerical Analysis S(pfd2^
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by Weimin Han B. Daya Reddy C;` fOCz^
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Springer 1999 @)B_e*6>'
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The basis for the modern theory of elastoplasticity was laid in the nineteenthcentury, ~X/T6(n$
by Tresca, St. Venant, L´evy, and Bauschinger. Further y4') !e
major advances followed in the early part of this century, the chief contributors myXV~6R
3
during this period being Prandtl, von Mises, and Reuss. This -nW-I\d%
early phase in the history of elastoplasticity was characterized by the introduction \iFE,z
and development of the concepts of irreversible behavior, yield (ZYOm
criteria, hardening and perfect plasticity, and of rate or incremental constitutive <qBPN{'a"
equations for the plastic strain. mN{$z<r
Greater clarity in the mathematical framework for elastoplasticity theory kcle|B
came with the contributions of Prager, Drucker, and Hill, during the 7j+.H/2
period just after the Second World War. Convexity of yield surfaces, and t%)L8%Jr
all its ramifications, was a central theme in this phase of the development $aG'.0HW
of the theory. kHO\#fF<
The mathematical community, meanwhile, witnessed a burst of progress Nn$$yUkMX
in the theory of partial differential equations and variational inequalities VaB7)r
from the early 1960s onwards. The timing of this set of developments was Vr'Z5F*@
particularly fortuitous for plasticity, given the fairly mature state of the [kCn6\_<V
subject, and the realization that the natural framework for the study of 2rxdRg'YLQ
initial boundary value problems in elastoplasticity was that of variational x;+,lP
inequalities. This confluence of subjects emanating from mechanics and (H$eXW7
mathematics resulted in yet further theoretical developments, the outstanding wgrYZ^]
examples being the articles by Moreau, and the monographs &7 ,wdG
by Duvaut and J.-L. Lions, and Temam. In this manner the stage was *M{1RMc
set for comprehensive investigations of the well-posedness of problems in 2}NfR8
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elastoplasticity, while the simultaneous rapid growth in interest in numer- B~^\jRd"
ical methods ensured that equal attention was given to issues such as the ^JTfRZ:a
development of solution algorithms, and their convergences. %UmE=V
The interaction between elastoplasticity and mathematics has spawned bnlL-]]9z
among many engineering scientists an interest in gaining a better understanding *G9;d0
of the modern mathematical developments in the subject. In the (/%}a`2#o
same way, given the richness of plasticity in interesting and important m2;%|QE(
mathematical problems, many mathematicians, either students or mature <^=k~7m
researchers, have developed an interest in understanding the mechanical PSRGlxdO
and engineering basis of the subject, and its connections with the mathematical L@/+u+j0
theory. While there are many textbooks and monographs on plasticity KksbhN{AB
that deal with the mechanics of the subject, they are written mainly Z"n]y4h
for a readership in the engineering sciences; there does not appear to us C oaqi`v4T
to have existed an extended account of elastoplasticity which would serve 2dC)%]aLme
these dual needs of both engineering scientists and mathematicians. It is 1yhx)m;f
our hope that this monograph will go some way towards filling that gap. !MbRI
We present in this work three logically connected aspects of the theory of G
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elastic-plastic solids: the constitutive theory, the variational formulations of _?{2{^v
the related initial boundary value problems, and the numerical analysis of 6c2fqAF>i
these problems. These three aspects determine the three parts into which .m<-)Kx
the monograph is divided. BjA|H
The constitutive theory, which is the subject of Part I, begins with a !%Ak15o
motivation grounded in physical experience, whereafter the constitutive W?@ ;(k
theory of classical elastoplastic media is developed. This theory is then cast RKe19l_V
in a convex analytic setting, after some salient results from convex analysis E( TY%wO
have been reviewed. The term “classical” refers in this work to that theory U}UIbJD*=
of elastic-plastic material behavior which is based on the notion of convex "PX~Yc
yield surfaces, and the normality law. Furthermore, only the small strain, 9`xq3EL2T
quasi-static theory is treated. Much of what is covered in Part I will be XLtuck
familiar to those working on plasticity, though the greater insights offered `p!.K9r7
by exploiting the tools of convex analysis may be new to some researchers. rTi.k
On the other hand, mathematicians unfamiliar with plasticity theory will ^#G>P0mG%
find in this first part an introduction that is self-contained and accessible. })J]D~!p
Part II of the monograph is concerned with the variational problems in wtZe\h
elastoplasticity. Two major problems are identified and treated: the primal 9U+^8,5
problem, of which the displacement and internal variables are the primary U*-%V$3+w5
unknowns; and the dual problem, of which the main unknowns are the DU;]Q:r{
generalized stresses. 8}U/fQ~
Finally, Part III is devoted to a treatment of the approximation of the zRe0z2
variational problems presented in the previous part. We focus on finite element +Y.As
approximations in space, and both semi- and fully discrete problems. =/zQJzN
In addition to deriving error estimates for these approximations, attention |_O1V{Q=
is given to the behavior of those solution algorithms that are in common }\1V;T
use. 1r;Q5[@
Wherever possible we provide background materials of sufficient depth * 6uiOtH
to make this work as self-contained as possible. Thus, Part I contains a lY6U $*9c
Preface ix j*CnnM#n
review of topics in continuum mechanics, thermodynamics, linear elasticity, >9|Q,/b0
and convex analytic setting of elastoplasticity. In Part II we include a 'HOt?lpu!
treatment of those topics from functional analysis and function spaces that blLX ncyD
are relevant to a discussion of the well-posedness of vatriational problems. m^TkFt<BM
And Part III begins with an overview of the mathematics of finite elements. jildiT[s
In writing this work we have drawn heavily on the results of our joint collaboration [9w8oNg0
in the past few years. We have also consulted, and made liberal l!`m}$
use of the works of many: we mention in particular the major contributions Q 5Ln'La$
of G. Duvaut and J.-L. Lions, C. Johnson, J.B. Martin, H. d~.#K S
Matthies, and J.C. Simo. While we acknowledge this debt with gratitude, A>X#[qx
the responsibility for any inaccuracies or erroneous interpretations o<x2,uT
that might exist in this work, rests with its authors. p}C3<[Nk
We thank our many friends, colleagues and family members whose interest, _Wgg=A"G
guidance, and encouragement made this work possible. ]+J]}C]\d
W.H. ?A]:`l_"
Iowa City \wTWhr0
B.D.R. AR&u9Y)I
Cape Town