Plasticity - Mathematical Theory and Numerical Analysis pn.T~"%
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by Weimin Han B. Daya Reddy :E@3Vl#U
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Springer 1999 E7Y`|nT
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The basis for the modern theory of elastoplasticity was laid in the nineteenthcentury, 'Ub
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by Tresca, St. Venant, L´evy, and Bauschinger. Further !cAyTl(_
major advances followed in the early part of this century, the chief contributors \&i P`v`K
during this period being Prandtl, von Mises, and Reuss. This `P8Vh+7u
early phase in the history of elastoplasticity was characterized by the introduction g47-db"5
and development of the concepts of irreversible behavior, yield W034N[9
criteria, hardening and perfect plasticity, and of rate or incremental constitutive /Ya_>+oo
equations for the plastic strain. J~1r{5V4{
Greater clarity in the mathematical framework for elastoplasticity theory B{C??g8/
came with the contributions of Prager, Drucker, and Hill, during the Xp8]qH|K
period just after the Second World War. Convexity of yield surfaces, and eL\;Nf+Zp
all its ramifications, was a central theme in this phase of the development *i- _6s
of the theory. cgm~>
The mathematical community, meanwhile, witnessed a burst of progress f/Hm{<BY
in the theory of partial differential equations and variational inequalities .72S o T
from the early 1960s onwards. The timing of this set of developments was EVVP]ND
particularly fortuitous for plasticity, given the fairly mature state of the d\61;C
subject, and the realization that the natural framework for the study of @g$Gti
initial boundary value problems in elastoplasticity was that of variational JNa"8
inequalities. This confluence of subjects emanating from mechanics and Tp-l^?O-p
mathematics resulted in yet further theoretical developments, the outstanding mqAWL:VvQ7
examples being the articles by Moreau, and the monographs L_+k12lm
by Duvaut and J.-L. Lions, and Temam. In this manner the stage was !>e5z|1
set for comprehensive investigations of the well-posedness of problems in KOp162X>r
elastoplasticity, while the simultaneous rapid growth in interest in numer- 'F_8j;
ical methods ensured that equal attention was given to issues such as the X(\fN[;
development of solution algorithms, and their convergences. ~YRDyQ:%T
The interaction between elastoplasticity and mathematics has spawned G_k~X"
among many engineering scientists an interest in gaining a better understanding I>[RqG
of the modern mathematical developments in the subject. In the !2'jrJGc
same way, given the richness of plasticity in interesting and important L?Qg#YSd~
mathematical problems, many mathematicians, either students or mature dUF&."pW e
researchers, have developed an interest in understanding the mechanical JoN\]JL\,
and engineering basis of the subject, and its connections with the mathematical u
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theory. While there are many textbooks and monographs on plasticity E gal4
that deal with the mechanics of the subject, they are written mainly #z2rzM@/:
for a readership in the engineering sciences; there does not appear to us 4)"n
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to have existed an extended account of elastoplasticity which would serve 'C
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these dual needs of both engineering scientists and mathematicians. It is 8-_QFgY
our hope that this monograph will go some way towards filling that gap. bX*Hi#J~A
We present in this work three logically connected aspects of the theory of &b?LP]
elastic-plastic solids: the constitutive theory, the variational formulations of f3H ed
the related initial boundary value problems, and the numerical analysis of G-He" 4& $
these problems. These three aspects determine the three parts into which DiEluA&w9
the monograph is divided. M5*{
The constitutive theory, which is the subject of Part I, begins with a -R%<.]fJ
motivation grounded in physical experience, whereafter the constitutive &*7?)eI!i
theory of classical elastoplastic media is developed. This theory is then cast ]"1`+q6i
in a convex analytic setting, after some salient results from convex analysis 0LfU=X0#7
have been reviewed. The term “classical” refers in this work to that theory 6C-/`>m
of elastic-plastic material behavior which is based on the notion of convex 1Lg-.-V
yield surfaces, and the normality law. Furthermore, only the small strain, +S R+x/?z
quasi-static theory is treated. Much of what is covered in Part I will be z[cyA.
familiar to those working on plasticity, though the greater insights offered HKqwE=NZ
by exploiting the tools of convex analysis may be new to some researchers. )YX 'N<[
On the other hand, mathematicians unfamiliar with plasticity theory will |/2y-[;:
find in this first part an introduction that is self-contained and accessible. qd#sY.|1
Part II of the monograph is concerned with the variational problems in p"FW&Q=PN
elastoplasticity. Two major problems are identified and treated: the primal <0QH<4
problem, of which the displacement and internal variables are the primary )Lwc
unknowns; and the dual problem, of which the main unknowns are the 5fm?Lxr&?
generalized stresses. NDs!a
Finally, Part III is devoted to a treatment of the approximation of the mXUGe:e8
variational problems presented in the previous part. We focus on finite element DWID$w
approximations in space, and both semi- and fully discrete problems. (q4),y<:[
In addition to deriving error estimates for these approximations, attention q&Gz ]
is given to the behavior of those solution algorithms that are in common eOXHQjuj
use. &p}$J)q
Wherever possible we provide background materials of sufficient depth 8 XICF
to make this work as self-contained as possible. Thus, Part I contains a $`wMX{
Preface ix H~+ l7OhV
review of topics in continuum mechanics, thermodynamics, linear elasticity, awOd_![c'
and convex analytic setting of elastoplasticity. In Part II we include a mFSw@CC
treatment of those topics from functional analysis and function spaces that H]$)Eg%6
are relevant to a discussion of the well-posedness of vatriational problems. lNL6M%e$Q
And Part III begins with an overview of the mathematics of finite elements. #%D_Y33;
In writing this work we have drawn heavily on the results of our joint collaboration t: IN,Kl4
in the past few years. We have also consulted, and made liberal MH{GR)ng:9
use of the works of many: we mention in particular the major contributions 05spovO/'
of G. Duvaut and J.-L. Lions, C. Johnson, J.B. Martin, H. z%e8K(
Matthies, and J.C. Simo. While we acknowledge this debt with gratitude, X83 w@-$}
the responsibility for any inaccuracies or erroneous interpretations +\|Iu;w
that might exist in this work, rests with its authors. ;Y;qg
We thank our many friends, colleagues and family members whose interest, @~#Ym1{W
guidance, and encouragement made this work possible. e][B7wZ
W.H. lK4M.QV
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Iowa City ;Wl+zw
B.D.R. -,+q#F
Cape Town