Plasticity - Mathematical Theory and Numerical Analysis W'=}2Y$]u
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by Weimin Han B. Daya Reddy )#1!%aQ
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Springer 1999 WMW=RgiW\
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The basis for the modern theory of elastoplasticity was laid in the nineteenthcentury, s|:1z"q
by Tresca, St. Venant, L´evy, and Bauschinger. Further AC 2kG
major advances followed in the early part of this century, the chief contributors pr1bsrMuL
during this period being Prandtl, von Mises, and Reuss. This ,t;US.s([.
early phase in the history of elastoplasticity was characterized by the introduction m>F:dI
and development of the concepts of irreversible behavior, yield I-1NZgv
criteria, hardening and perfect plasticity, and of rate or incremental constitutive fP6.
equations for the plastic strain. FC~%G&K/q^
Greater clarity in the mathematical framework for elastoplasticity theory h@'CmIZc
came with the contributions of Prager, Drucker, and Hill, during the RnU7|p{
period just after the Second World War. Convexity of yield surfaces, and p@Cas
all its ramifications, was a central theme in this phase of the development 3IjsV5a
of the theory. ]T&d_~l
The mathematical community, meanwhile, witnessed a burst of progress Ud2Tn*QmI
in the theory of partial differential equations and variational inequalities )y Zr]
from the early 1960s onwards. The timing of this set of developments was k4!_(X%8
particularly fortuitous for plasticity, given the fairly mature state of the |:Maa6(W
subject, and the realization that the natural framework for the study of @$t\yBSK
initial boundary value problems in elastoplasticity was that of variational ?Bl/bY$*h
inequalities. This confluence of subjects emanating from mechanics and QSn18V>{
mathematics resulted in yet further theoretical developments, the outstanding _<DOA:'v
examples being the articles by Moreau, and the monographs #D%6b
by Duvaut and J.-L. Lions, and Temam. In this manner the stage was 8h4]<T
set for comprehensive investigations of the well-posedness of problems in -'L~Y~'.
elastoplasticity, while the simultaneous rapid growth in interest in numer- C(h Td%
ical methods ensured that equal attention was given to issues such as the CEBG9[|
development of solution algorithms, and their convergences. |W$|og'wC
The interaction between elastoplasticity and mathematics has spawned Lz p}<B
among many engineering scientists an interest in gaining a better understanding 7-Oa34ba+
of the modern mathematical developments in the subject. In the EaHJl
same way, given the richness of plasticity in interesting and important `@WJ_-$#
mathematical problems, many mathematicians, either students or mature 5W&L cBB
researchers, have developed an interest in understanding the mechanical =yM%#{t&W
and engineering basis of the subject, and its connections with the mathematical 6w(r}yO]
theory. While there are many textbooks and monographs on plasticity kM1N4N7
that deal with the mechanics of the subject, they are written mainly bBXLW}W
for a readership in the engineering sciences; there does not appear to us ^c>Bh[
to have existed an extended account of elastoplasticity which would serve I} 5e{jBB
these dual needs of both engineering scientists and mathematicians. It is }@ktAt
our hope that this monograph will go some way towards filling that gap. >}Bcv%zZ
We present in this work three logically connected aspects of the theory of H~mp*S
elastic-plastic solids: the constitutive theory, the variational formulations of (9TSH3f?
the related initial boundary value problems, and the numerical analysis of ~Hv>^u
Mh
these problems. These three aspects determine the three parts into which olA+B
the monograph is divided. 5o>*a>27,A
The constitutive theory, which is the subject of Part I, begins with a m[iQ7/
motivation grounded in physical experience, whereafter the constitutive _Y/*e<bU
theory of classical elastoplastic media is developed. This theory is then cast sWMln:=
in a convex analytic setting, after some salient results from convex analysis r>i95u82'
have been reviewed. The term “classical” refers in this work to that theory >3ZhPvE-p'
of elastic-plastic material behavior which is based on the notion of convex I"x~ 7
yield surfaces, and the normality law. Furthermore, only the small strain, l?rLadvc
quasi-static theory is treated. Much of what is covered in Part I will be rnQ_0d
familiar to those working on plasticity, though the greater insights offered -Ah&|!/
by exploiting the tools of convex analysis may be new to some researchers. ?*yB&(a:8
On the other hand, mathematicians unfamiliar with plasticity theory will *h=>*t?I2
find in this first part an introduction that is self-contained and accessible. 3 =c#LUA`
Part II of the monograph is concerned with the variational problems in &Td)2Wt
elastoplasticity. Two major problems are identified and treated: the primal 4[JF.O6}
problem, of which the displacement and internal variables are the primary )G?\{n-
unknowns; and the dual problem, of which the main unknowns are the Y'bz>@1(
generalized stresses. *5*#Z~dut8
Finally, Part III is devoted to a treatment of the approximation of the GvgTbCxnN
variational problems presented in the previous part. We focus on finite element V/#J>-os}W
approximations in space, and both semi- and fully discrete problems. rIYO(}Fl
In addition to deriving error estimates for these approximations, attention ~k?wnw
is given to the behavior of those solution algorithms that are in common _x3=i\O,
use. WiB~sIp
Wherever possible we provide background materials of sufficient depth sQ^t8Y9
to make this work as self-contained as possible. Thus, Part I contains a %6rSLBw3
Preface ix @1gURx&2_
review of topics in continuum mechanics, thermodynamics, linear elasticity, nnN$?'%~6
and convex analytic setting of elastoplasticity. In Part II we include a =Ry8E2NuM
treatment of those topics from functional analysis and function spaces that o|y_j49
are relevant to a discussion of the well-posedness of vatriational problems. ~m,~;
And Part III begins with an overview of the mathematics of finite elements. ,Wu$@jD/]
In writing this work we have drawn heavily on the results of our joint collaboration qsXkm4
in the past few years. We have also consulted, and made liberal Yt,MXm\
use of the works of many: we mention in particular the major contributions _KkaseR
of G. Duvaut and J.-L. Lions, C. Johnson, J.B. Martin, H. @9n|5.i
Matthies, and J.C. Simo. While we acknowledge this debt with gratitude, 0bc>yZ\R
the responsibility for any inaccuracies or erroneous interpretations ]h'
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that might exist in this work, rests with its authors. L-rV+?i`6f
We thank our many friends, colleagues and family members whose interest, :@"o.8p
guidance, and encouragement made this work possible. @ <2y+_e
W.H. 8 l)K3;q_
Iowa City "\`Fu
B.D.R.
-u<F>C
Cape Town