Plasticity - Mathematical Theory and Numerical Analysis 1R+/T
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by Weimin Han B. Daya Reddy <lo\7p$A
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Springer 1999 W Y]
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The basis for the modern theory of elastoplasticity was laid in the nineteenthcentury, :+qd>;yf#
by Tresca, St. Venant, L´evy, and Bauschinger. Further QK`5KB(k'
major advances followed in the early part of this century, the chief contributors 3Hd~mfO\
during this period being Prandtl, von Mises, and Reuss. This !5}u \
early phase in the history of elastoplasticity was characterized by the introduction Y*Ra!]62
and development of the concepts of irreversible behavior, yield s1GR!*z>
criteria, hardening and perfect plasticity, and of rate or incremental constitutive p"UdD
equations for the plastic strain. N a$eeM
Greater clarity in the mathematical framework for elastoplasticity theory L<62-+e`
came with the contributions of Prager, Drucker, and Hill, during the G8t9Lx
period just after the Second World War. Convexity of yield surfaces, and iX|K4.Pz{
all its ramifications, was a central theme in this phase of the development 9{KL^O?g
of the theory. 'OTQiI^t=
The mathematical community, meanwhile, witnessed a burst of progress \~!!h.xR
in the theory of partial differential equations and variational inequalities *
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from the early 1960s onwards. The timing of this set of developments was CVt:tV
particularly fortuitous for plasticity, given the fairly mature state of the 8%ea(|Wjg
subject, and the realization that the natural framework for the study of };Oyv7D+b
initial boundary value problems in elastoplasticity was that of variational rijavZS6
inequalities. This confluence of subjects emanating from mechanics and rn9n _)
mathematics resulted in yet further theoretical developments, the outstanding V*<`!w
examples being the articles by Moreau, and the monographs Oe~x,=X)
by Duvaut and J.-L. Lions, and Temam. In this manner the stage was !jTtMx
set for comprehensive investigations of the well-posedness of problems in @?vC4+'
elastoplasticity, while the simultaneous rapid growth in interest in numer- [^S(SPL
ical methods ensured that equal attention was given to issues such as the PptVneujI
development of solution algorithms, and their convergences. 3HEm-pok
The interaction between elastoplasticity and mathematics has spawned R9z:K_d,
among many engineering scientists an interest in gaining a better understanding )p^" J|
of the modern mathematical developments in the subject. In the [(rT,31cW
same way, given the richness of plasticity in interesting and important r&y0`M
mathematical problems, many mathematicians, either students or mature
B8~JUGD
researchers, have developed an interest in understanding the mechanical 2t,N9@u=UN
and engineering basis of the subject, and its connections with the mathematical X;&Iu{&=
theory. While there are many textbooks and monographs on plasticity J{!U;r!6
that deal with the mechanics of the subject, they are written mainly /f}!G
for a readership in the engineering sciences; there does not appear to us |Fi{]9(G2
to have existed an extended account of elastoplasticity which would serve je`Ysbe n
these dual needs of both engineering scientists and mathematicians. It is 6|G&d>G$_
our hope that this monograph will go some way towards filling that gap. JJZu%9~[
We present in this work three logically connected aspects of the theory of 0;Oe&Y
elastic-plastic solids: the constitutive theory, the variational formulations of >2t.7UhDI
the related initial boundary value problems, and the numerical analysis of yCvP-?2
these problems. These three aspects determine the three parts into which 4Y5lP00!}
the monograph is divided. ?l9j]
The constitutive theory, which is the subject of Part I, begins with a $Vp*,oRL
motivation grounded in physical experience, whereafter the constitutive -Is;cbfLj/
theory of classical elastoplastic media is developed. This theory is then cast .US=fWyrb
in a convex analytic setting, after some salient results from convex analysis !y\r.fm!A
have been reviewed. The term “classical” refers in this work to that theory [2$mo;E?
of elastic-plastic material behavior which is based on the notion of convex L}a-c(G+8
yield surfaces, and the normality law. Furthermore, only the small strain, ?` lD|~
quasi-static theory is treated. Much of what is covered in Part I will be kfV}ta'^S
familiar to those working on plasticity, though the greater insights offered \5iMr[s
by exploiting the tools of convex analysis may be new to some researchers. .<Rw16O
On the other hand, mathematicians unfamiliar with plasticity theory will 0Fw4}f.o
find in this first part an introduction that is self-contained and accessible. B{ A b#
Part II of the monograph is concerned with the variational problems in DEw>f%&4
elastoplasticity. Two major problems are identified and treated: the primal :*} -,{uX
problem, of which the displacement and internal variables are the primary T@%\?=P
unknowns; and the dual problem, of which the main unknowns are the 'EHtA9M
generalized stresses. ?yc{@|
Finally, Part III is devoted to a treatment of the approximation of the v8} vk]b
variational problems presented in the previous part. We focus on finite element v6M4KC2?
approximations in space, and both semi- and fully discrete problems. .sCj3sX*
In addition to deriving error estimates for these approximations, attention y<g1q"F
is given to the behavior of those solution algorithms that are in common VtN1 [}
use. [o"<DP6w
Wherever possible we provide background materials of sufficient depth K2> CR$L
to make this work as self-contained as possible. Thus, Part I contains a ?:$\
t?e^
Preface ix { )-8P
review of topics in continuum mechanics, thermodynamics, linear elasticity, , UsY0YC
and convex analytic setting of elastoplasticity. In Part II we include a !sG#3sUe[
treatment of those topics from functional analysis and function spaces that 2<FEn$n[
are relevant to a discussion of the well-posedness of vatriational problems. SNJSRqWL/
And Part III begins with an overview of the mathematics of finite elements. +6`+Q2qi
In writing this work we have drawn heavily on the results of our joint collaboration dM=45$\q
in the past few years. We have also consulted, and made liberal fg)VO6Wo&
use of the works of many: we mention in particular the major contributions bQ3txuha
of G. Duvaut and J.-L. Lions, C. Johnson, J.B. Martin, H. mPL0s
Matthies, and J.C. Simo. While we acknowledge this debt with gratitude, DYDeb i6
the responsibility for any inaccuracies or erroneous interpretations W=:AOBK
that might exist in this work, rests with its authors. F1)5"7f
We thank our many friends, colleagues and family members whose interest, C<Z{G%Qm
guidance, and encouragement made this work possible. 2Onp{,'}
W.H. U EjP`
Iowa City :o 8XG
B.D.R. lDSF
Cape Town