Plasticity - Mathematical Theory and Numerical Analysis \?d3Pn5`
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by Weimin Han B. Daya Reddy [104;g <
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Springer 1999 uTxa5j
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The basis for the modern theory of elastoplasticity was laid in the nineteenthcentury, weSq|f
by Tresca, St. Venant, L´evy, and Bauschinger. Further >
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major advances followed in the early part of this century, the chief contributors kB> ~Tb0
during this period being Prandtl, von Mises, and Reuss. This NOuG# P
early phase in the history of elastoplasticity was characterized by the introduction X
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and development of the concepts of irreversible behavior, yield D**GC
criteria, hardening and perfect plasticity, and of rate or incremental constitutive >
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equations for the plastic strain. #F.jf2h@
Greater clarity in the mathematical framework for elastoplasticity theory 6e B;
came with the contributions of Prager, Drucker, and Hill, during the ;,C]WZ.w
period just after the Second World War. Convexity of yield surfaces, and CMaph
all its ramifications, was a central theme in this phase of the development R2gV(L(!!
of the theory. 52dD(
The mathematical community, meanwhile, witnessed a burst of progress PmRvjSIG
in the theory of partial differential equations and variational inequalities ylKK!vRHT
from the early 1960s onwards. The timing of this set of developments was {^
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particularly fortuitous for plasticity, given the fairly mature state of the v$W[(
subject, and the realization that the natural framework for the study of ^Aq0<
initial boundary value problems in elastoplasticity was that of variational . \"k49M`
inequalities. This confluence of subjects emanating from mechanics and
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mathematics resulted in yet further theoretical developments, the outstanding 0{|HRiQH9+
examples being the articles by Moreau, and the monographs ]MV8rC[\
by Duvaut and J.-L. Lions, and Temam. In this manner the stage was O,%,dtD[a
set for comprehensive investigations of the well-posedness of problems in sfj+-se(K.
elastoplasticity, while the simultaneous rapid growth in interest in numer- w{6C4~0
ical methods ensured that equal attention was given to issues such as the DzQBWY]
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development of solution algorithms, and their convergences. $Sgf jm
The interaction between elastoplasticity and mathematics has spawned :Iv;%a0 -
among many engineering scientists an interest in gaining a better understanding :Ko6.|
of the modern mathematical developments in the subject. In the ksOGCd^G7
same way, given the richness of plasticity in interesting and important ~vF a\7sf
mathematical problems, many mathematicians, either students or mature \ph.c*c
researchers, have developed an interest in understanding the mechanical
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and engineering basis of the subject, and its connections with the mathematical u]};QR
theory. While there are many textbooks and monographs on plasticity 4
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that deal with the mechanics of the subject, they are written mainly YR9fw
for a readership in the engineering sciences; there does not appear to us *iEtXv
to have existed an extended account of elastoplasticity which would serve A913*O:\
these dual needs of both engineering scientists and mathematicians. It is lGl'A}]#$
our hope that this monograph will go some way towards filling that gap. n%s%i-[5B
We present in this work three logically connected aspects of the theory of &~
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elastic-plastic solids: the constitutive theory, the variational formulations of NEIkG>\7q
the related initial boundary value problems, and the numerical analysis of |4Q*4s
these problems. These three aspects determine the three parts into which >F7w]XH
the monograph is divided. 9)ALJd,M
The constitutive theory, which is the subject of Part I, begins with a *[3xc*5F/A
motivation grounded in physical experience, whereafter the constitutive ds(?:zx#
theory of classical elastoplastic media is developed. This theory is then cast _!R$a-
in a convex analytic setting, after some salient results from convex analysis Aw |;C
have been reviewed. The term “classical” refers in this work to that theory 15\m.Ix
of elastic-plastic material behavior which is based on the notion of convex }OL"38P
yield surfaces, and the normality law. Furthermore, only the small strain, rtRbr_
quasi-static theory is treated. Much of what is covered in Part I will be `t&{^ a&Y"
familiar to those working on plasticity, though the greater insights offered S3E,0%yo+)
by exploiting the tools of convex analysis may be new to some researchers. |)29"_Kk5
On the other hand, mathematicians unfamiliar with plasticity theory will LdV&G/G-#D
find in this first part an introduction that is self-contained and accessible. hTr5Q33y>
Part II of the monograph is concerned with the variational problems in S{rltT-
elastoplasticity. Two major problems are identified and treated: the primal 7{L4a\JzT
problem, of which the displacement and internal variables are the primary /Hyz]46
unknowns; and the dual problem, of which the main unknowns are the VN0We<\Z
generalized stresses. ^Tm`motzh
Finally, Part III is devoted to a treatment of the approximation of the CwA_jOp
variational problems presented in the previous part. We focus on finite element s|]g@czan
approximations in space, and both semi- and fully discrete problems. ViPC Yt`of
In addition to deriving error estimates for these approximations, attention DAB9-[y+
is given to the behavior of those solution algorithms that are in common X#lNS+&='
use. [|DKBJ
Wherever possible we provide background materials of sufficient depth (~=.[Y
to make this work as self-contained as possible. Thus, Part I contains a sQvRupYRO
Preface ix En?V\|,
review of topics in continuum mechanics, thermodynamics, linear elasticity, VThr]$2Y
and convex analytic setting of elastoplasticity. In Part II we include a DK)W
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treatment of those topics from functional analysis and function spaces that aa`(2%(:
are relevant to a discussion of the well-posedness of vatriational problems. K^shT h8k
And Part III begins with an overview of the mathematics of finite elements. ej`%}e%2
In writing this work we have drawn heavily on the results of our joint collaboration jO-?t9^
in the past few years. We have also consulted, and made liberal a>'ez0C
use of the works of many: we mention in particular the major contributions @h%V:c
of G. Duvaut and J.-L. Lions, C. Johnson, J.B. Martin, H. XH"+oW
Matthies, and J.C. Simo. While we acknowledge this debt with gratitude, `}}:9d
the responsibility for any inaccuracies or erroneous interpretations /x6p
that might exist in this work, rests with its authors. :"\,iH
We thank our many friends, colleagues and family members whose interest, 5^u$zfR
guidance, and encouragement made this work possible. \^c4v\s<o#
W.H. ?pTX4a&>
Iowa City wZiUzS;v
B.D.R. D(#f`Fj;
Cape Town