Plasticity - Mathematical Theory and Numerical Analysis (pAGS{{
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by Weimin Han B. Daya Reddy
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Springer 1999 HogT#BMs
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The basis for the modern theory of elastoplasticity was laid in the nineteenthcentury, 8E|S`I
by Tresca, St. Venant, L´evy, and Bauschinger. Further ^f@EDG8
major advances followed in the early part of this century, the chief contributors o@"H3
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during this period being Prandtl, von Mises, and Reuss. This AuWEy-q?
early phase in the history of elastoplasticity was characterized by the introduction 6VIi
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and development of the concepts of irreversible behavior, yield iEnDS@7
criteria, hardening and perfect plasticity, and of rate or incremental constitutive m&fm<?|
equations for the plastic strain. )/Ul"QF
Greater clarity in the mathematical framework for elastoplasticity theory 2b2/jzO}J
came with the contributions of Prager, Drucker, and Hill, during the b1_HDC(
period just after the Second World War. Convexity of yield surfaces, and RHeql*`
all its ramifications, was a central theme in this phase of the development bz,C%HFA
of the theory. =`u4xa#m
The mathematical community, meanwhile, witnessed a burst of progress 10t9Qv/
in the theory of partial differential equations and variational inequalities U#-89.x
from the early 1960s onwards. The timing of this set of developments was PY~cu@'k{
particularly fortuitous for plasticity, given the fairly mature state of the :H3qa2p
subject, and the realization that the natural framework for the study of TTu<~GH
initial boundary value problems in elastoplasticity was that of variational wU+-;C5e
inequalities. This confluence of subjects emanating from mechanics and iku) otUc
mathematics resulted in yet further theoretical developments, the outstanding R0AVAUG
examples being the articles by Moreau, and the monographs jo/-'Lf{?
by Duvaut and J.-L. Lions, and Temam. In this manner the stage was L-vy,[9)[*
set for comprehensive investigations of the well-posedness of problems in
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elastoplasticity, while the simultaneous rapid growth in interest in numer- 66!cfpM
ical methods ensured that equal attention was given to issues such as the QF
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development of solution algorithms, and their convergences. Q`'w)aV
The interaction between elastoplasticity and mathematics has spawned g"^<LX-
among many engineering scientists an interest in gaining a better understanding i#=s_v8
of the modern mathematical developments in the subject. In the (@[c;+x
same way, given the richness of plasticity in interesting and important SBZqO'}7
mathematical problems, many mathematicians, either students or mature +O2T%
researchers, have developed an interest in understanding the mechanical n}}$-xl
and engineering basis of the subject, and its connections with the mathematical \= =rdW-
theory. While there are many textbooks and monographs on plasticity .gzNdSE
that deal with the mechanics of the subject, they are written mainly }HRM6fR1S
for a readership in the engineering sciences; there does not appear to us (w`9*1NO
to have existed an extended account of elastoplasticity which would serve #[ipJ %
these dual needs of both engineering scientists and mathematicians. It is oYI7 .w
our hope that this monograph will go some way towards filling that gap. }y;s(4
We present in this work three logically connected aspects of the theory of 9Eu.Y
elastic-plastic solids: the constitutive theory, the variational formulations of 3%p^>D\
the related initial boundary value problems, and the numerical analysis of #Fm, mO$v
these problems. These three aspects determine the three parts into which ?%(:
the monograph is divided. f+d[Q1
The constitutive theory, which is the subject of Part I, begins with a 4'_PLOgnX
motivation grounded in physical experience, whereafter the constitutive ~QQi{92
theory of classical elastoplastic media is developed. This theory is then cast ef *Vs
in a convex analytic setting, after some salient results from convex analysis rI23e[
have been reviewed. The term “classical” refers in this work to that theory R,>LUa*u
of elastic-plastic material behavior which is based on the notion of convex ,*!HN
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yield surfaces, and the normality law. Furthermore, only the small strain, _vr>-:G
quasi-static theory is treated. Much of what is covered in Part I will be 3+ JkV\AF
familiar to those working on plasticity, though the greater insights offered R9xhO!
by exploiting the tools of convex analysis may be new to some researchers. xJlf}LEyF
On the other hand, mathematicians unfamiliar with plasticity theory will 86y)+h`
find in this first part an introduction that is self-contained and accessible. OXAr..
Part II of the monograph is concerned with the variational problems in K*NCIIDh
elastoplasticity. Two major problems are identified and treated: the primal ^M_0M
problem, of which the displacement and internal variables are the primary jbZ%Y0km%
unknowns; and the dual problem, of which the main unknowns are the gE;r;#Jt4
generalized stresses. 'So,*>]63
Finally, Part III is devoted to a treatment of the approximation of the ^}8qPBz
variational problems presented in the previous part. We focus on finite element Y)lYEhF
approximations in space, and both semi- and fully discrete problems. %PW_v~sg
In addition to deriving error estimates for these approximations, attention RE6dN
is given to the behavior of those solution algorithms that are in common H!PMb{e
use. Hwiw:lPq`E
Wherever possible we provide background materials of sufficient depth }04EM
to make this work as self-contained as possible. Thus, Part I contains a 1g<jr.
Preface ix %s&l^&ux
review of topics in continuum mechanics, thermodynamics, linear elasticity, aGSix}b1P
and convex analytic setting of elastoplasticity. In Part II we include a xL&M8:
treatment of those topics from functional analysis and function spaces that AYb-BaIc
are relevant to a discussion of the well-posedness of vatriational problems. I5Vp%mCY
And Part III begins with an overview of the mathematics of finite elements. 9
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In writing this work we have drawn heavily on the results of our joint collaboration Ps<;DE\$f4
in the past few years. We have also consulted, and made liberal _3YZz$07
use of the works of many: we mention in particular the major contributions 'ONCz
of G. Duvaut and J.-L. Lions, C. Johnson, J.B. Martin, H. {^(h*zxn
Matthies, and J.C. Simo. While we acknowledge this debt with gratitude, ^6g^ Q*"
the responsibility for any inaccuracies or erroneous interpretations 9+S$,|9
that might exist in this work, rests with its authors. e,V @t%
We thank our many friends, colleagues and family members whose interest, >x'R7z23
guidance, and encouragement made this work possible. meJ%mY
W.H. Wl?0|{W
Iowa City .! 'SG6 q
B.D.R. wjEyU:
Cape Town