Plasticity - Mathematical Theory and Numerical Analysis Kc}FMu
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by Weimin Han B. Daya Reddy }m\
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Springer 1999 JY_+p9KfyQ
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The basis for the modern theory of elastoplasticity was laid in the nineteenthcentury, *`=V"nXw$|
by Tresca, St. Venant, L´evy, and Bauschinger. Further
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major advances followed in the early part of this century, the chief contributors z^ KrR
during this period being Prandtl, von Mises, and Reuss. This }7wQFKME
early phase in the history of elastoplasticity was characterized by the introduction c3g\*)Jz"F
and development of the concepts of irreversible behavior, yield :X,1KR
criteria, hardening and perfect plasticity, and of rate or incremental constitutive g>T'R Vb
equations for the plastic strain. /'!F \ kz
Greater clarity in the mathematical framework for elastoplasticity theory +w%MwPC7`
came with the contributions of Prager, Drucker, and Hill, during the po\Q Me
period just after the Second World War. Convexity of yield surfaces, and Z:u7`%
all its ramifications, was a central theme in this phase of the development AIN_.=]"?
of the theory. :
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The mathematical community, meanwhile, witnessed a burst of progress ^A;v|U
in the theory of partial differential equations and variational inequalities +8mfq\Y1
from the early 1960s onwards. The timing of this set of developments was |!flR? OU
particularly fortuitous for plasticity, given the fairly mature state of the wNcf7/ky
subject, and the realization that the natural framework for the study of qwiM.b5
initial boundary value problems in elastoplasticity was that of variational 6 @'v6 1'
inequalities. This confluence of subjects emanating from mechanics and QR\qGhQ~
mathematics resulted in yet further theoretical developments, the outstanding 'FO^VJ;ha
examples being the articles by Moreau, and the monographs hXmW,+1
by Duvaut and J.-L. Lions, and Temam. In this manner the stage was fL'
42
set for comprehensive investigations of the well-posedness of problems in r#d~($[93
elastoplasticity, while the simultaneous rapid growth in interest in numer- \62|w HX
ical methods ensured that equal attention was given to issues such as the "72
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development of solution algorithms, and their convergences. !H~G_?Mf\O
The interaction between elastoplasticity and mathematics has spawned 0waQw7
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among many engineering scientists an interest in gaining a better understanding .2Y"=|NdA
of the modern mathematical developments in the subject. In the cuW$%$F
same way, given the richness of plasticity in interesting and important &AoXv`l4
mathematical problems, many mathematicians, either students or mature . m@Sk`s
researchers, have developed an interest in understanding the mechanical }#a d
and engineering basis of the subject, and its connections with the mathematical oypX.nye_
theory. While there are many textbooks and monographs on plasticity ft?J|AG
that deal with the mechanics of the subject, they are written mainly `+Wl
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for a readership in the engineering sciences; there does not appear to us f.,S-1D]h
to have existed an extended account of elastoplasticity which would serve eiJ $}\qJL
these dual needs of both engineering scientists and mathematicians. It is 7z5AI!s_
our hope that this monograph will go some way towards filling that gap. @]gP"Pp
We present in this work three logically connected aspects of the theory of !C&}e8M|eX
elastic-plastic solids: the constitutive theory, the variational formulations of 7o'kdYJzo
the related initial boundary value problems, and the numerical analysis of }+,1G!?z
these problems. These three aspects determine the three parts into which )LKutN?tBy
the monograph is divided. OiJ1&Fz(
The constitutive theory, which is the subject of Part I, begins with a s-3vp
motivation grounded in physical experience, whereafter the constitutive ,K,n{3]
theory of classical elastoplastic media is developed. This theory is then cast !1-:1Whz8
in a convex analytic setting, after some salient results from convex analysis QE m6#y
have been reviewed. The term “classical” refers in this work to that theory
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of elastic-plastic material behavior which is based on the notion of convex Aum&U){yY
yield surfaces, and the normality law. Furthermore, only the small strain, Kw"7M~
quasi-static theory is treated. Much of what is covered in Part I will be BQ2DQ7q
familiar to those working on plasticity, though the greater insights offered w)5eD+n\-
by exploiting the tools of convex analysis may be new to some researchers. u4rG e!
On the other hand, mathematicians unfamiliar with plasticity theory will 'HH[[9Q
find in this first part an introduction that is self-contained and accessible. [Xg?sdQCI
Part II of the monograph is concerned with the variational problems in tb"UGa
elastoplasticity. Two major problems are identified and treated: the primal v`*!Bhc-
problem, of which the displacement and internal variables are the primary u01x}Ff~6
unknowns; and the dual problem, of which the main unknowns are the Bd31>
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generalized stresses. doW_vu
Finally, Part III is devoted to a treatment of the approximation of the #q6jE
variational problems presented in the previous part. We focus on finite element _ ?xORzO
approximations in space, and both semi- and fully discrete problems. ? R#-gvX%
In addition to deriving error estimates for these approximations, attention m!tB;:6
is given to the behavior of those solution algorithms that are in common Go=MG:`
use. 3l-8TR
Wherever possible we provide background materials of sufficient depth <;=?~QK%-
to make this work as self-contained as possible. Thus, Part I contains a o/)]z
Preface ix QZYD;&iY&
review of topics in continuum mechanics, thermodynamics, linear elasticity, "!+q0l1]@
and convex analytic setting of elastoplasticity. In Part II we include a p*8=($j4
treatment of those topics from functional analysis and function spaces that ,_F1g<^@u
are relevant to a discussion of the well-posedness of vatriational problems. (w6 024~
And Part III begins with an overview of the mathematics of finite elements. gcQ>:mi
In writing this work we have drawn heavily on the results of our joint collaboration wHEt;rc(
in the past few years. We have also consulted, and made liberal L|u\3.:
use of the works of many: we mention in particular the major contributions Kj;Q;Ii
of G. Duvaut and J.-L. Lions, C. Johnson, J.B. Martin, H. ?FA} ;?v
Matthies, and J.C. Simo. While we acknowledge this debt with gratitude, J
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the responsibility for any inaccuracies or erroneous interpretations &?#V*-;^
that might exist in this work, rests with its authors. '[I?G6
We thank our many friends, colleagues and family members whose interest, l _dWS9
guidance, and encouragement made this work possible. Gh>Rt=Qu%
W.H. gC>
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Iowa City [K9l>O
B.D.R. eYOwdTrq
Cape Town