The present Volume contains the contributions to the fourth meeting on Unilateral Problems in Structural Analysis, held at Capri on June 14 to 16,1989. The preceding meetings took place at Villa Emma, near Udine, on May 1982, at Ravello on September 1983 and again at Villa Emma on June 1985. Publication of the proceedings started with the second meeting; the two resulting volumes were published by Springer Verlag, Vienna, under the series Cism Courses and Lectures. Unilateral Problems appear as a singular example of confluence of interests: they are the object of the attention of pure and applied mathematicians, of specialists in Continuum Mechanics and engineers. The idea which gave origin to this series of meetings was that of putting together people coming from such different fields. The result was an extremely fruitful exchange of experiences; it contributed, we believe, to the improvement of the knowledge in the area. The contents of the present Volume reflects the composite character of the meeting. There are contributions in the mathematical theory (Has linger, Panagiotopoulos, Romano), and studies in classical problems of Mechanics such as unilateral contact with friction (Kalker, Klarbring, Licht, Telega), Plasticity (Corradi, Del Piero, Owen) and composite materials and structures (Bruno, Leonardi). Some contributions deal with not yet completely explored questions of unilateral dynamics (Guo, Jean); finally, a contribution (Bennati) concerns the comparatively new subject of masonry structures, in which the unilateral constraint enters at the constitutive level.

The volume collects the contributions presented at the second meeting on Unilateral Problems, organized by CISM and held near Udine in June 1985. It gives an updated account of the state-of-the-art in the field of unilateral problems, with an outlook on open problems and on perspectives of application to structural analysis. The topic is presently the object of growing interest and is undergoing very rapid development. One of the most noticeable characteristics of unilateral problems is their interdisciplinary nature; they involve sophisticated mathematics, fundamental questions in mechanics, modern techniques in numerical analysis, re-inspection of the present knowledge of physical phenomena, and engineering applications. This volume succeeds in collecting and coordinating contributions from all these areas. For this reason, it is an excellent source of information for researchers working in the field.

The book gives an overview on formulation, mathematical analysis and numerical solution procedures of contact problems. In this respect the book should be of value to applied mathematicians and engineers who are concerned with contact mechanics.

A companion to Geometric aspects . . . (see preceding entry). The 10 papers consider traditional applied mathematics emphasizing problems such as control and optimization in industrial design. No index. Acidic paper. Annotation copyright Book News, Inc. Portland, Or.

This book deals with the impact of uncertainty in input data on the outputs of mathematical models. Uncertain inputs as scalars, tensors, functions, or domain boundaries are considered. In practical terms, material parameters or constitutive laws, for instance, are uncertain, and quantities as local temperature, local mechanical stress, or local displacement are monitored. The goal of the worst scenario method is to extremize the quantity over the set of uncertain input data.A general mathematical scheme of the worst scenario method, including approximation by finite element methods, is presented, and then applied to various state problems modeled by differential equations or variational inequalities: nonlinear heat flow, Timoshenko beam vibration and buckling, plate buckling, contact problems in elasticity and thermoelasticity with and without friction, and various models of plastic deformation, to list some of the topics. Dozens of examples, figures, and tables are included.Although the book concentrates on the mathematical aspects of the subject, a substantial part is written in an accessible style and is devoted to various facets of uncertainty in modeling and to the state of the art techniques proposed to deal with uncertain input data.A chapter on sensitivity analysis and on functional and convex analysis is included for the reader's convenience.·Rigorous theory is established for the treatment of uncertainty in modeling· Uncertainty is considered in complex models based on partial differential equations or variational inequalities · Applications to nonlinear and linear problems with uncertain data are presented in detail: quasilinear steady heat flow, buckling of beams and plates, vibration of beams, frictional contact of bodies, several models of plastic deformation, and more ·Although emphasis is put on theoretical analysis and approximation techniques, numerical examples are also present·Main ideas and approaches used today to handle uncertainties in modeling are described in an accessible form·Fairly self-contained book

This book is the official proceedings of a conference on Numerical Methods in Approximation Theory which was held at the Mathematisches Forschungs institut in Oberwolfach during the week of November 24~30, 1991. It contains refereed and edited papers by 20 of the 49 participants. The book is dedicated to the memory of Prof. Lothar Collatz who main tained a long and active interest in numerical approximation. It is the ninth in a series of volumes published by Birkhiiuser resulting from conferences on the subject held at Oberwolfach, and co-organized by Prof. Collatz. We now briefly describe the contents of the book. The paper of BASZEN SKI, DELVOS and JESTER deals with blending using sine double series expan sions of functions defined on the unit square. In addition to giving explicit error estimates for partial sums and for interpolating sine polynomials, they also show that Boolean sums yield almost the same asymptotic error estimates as the conventional tensor-product approach, but with a reduced number of terms. The paper of BEATSON and LIGHT discusses approximation by quasi interpolants which are sums of scaled translates of a one-parameter family of functions. They do not require reproduction of low degree polynomials, but nevertheless are able to give error bounds and analyze quasi-interpolation based on Gaussians and exponentials. BINEV and JETTER deal with multivariate interpolation using shifts of a single basis function. They treat both gridded data and scattered data. As examples, they consider box splines and certain radial basis functions.

This book presents different formulations of the equations governing incompressible viscous flows, in the form needed for developing numerical solution procedures. The conditions required to satisfy the no-slip boundary conditions in the various formulations are discussed in detail. Rather than focussing on a particular spatial discretization method, the text provides a unitary view of several methods currently in use for the numerical solution of incompressible Navier-Stokes equations, using either finite differences, finite elements or spectral approximations. For each formulation, a complete statement of the mathematical problem is provided, comprising the various boundary, possibly integral, and initial conditions, suitable for any theoretical and/or computational development of the governing equations. The text is suitable for courses in fluid mechanics and computational fluid dynamics. It covers that part of the subject matter dealing with the equations for incompressible viscous flows and their determination by means of numerical methods. A substantial portion of the book contains new results and unpublished material.

Progress in today's high-technology industries is strongly associated with the development of new mathematical tools. A typical illustration of this partnership is the mathematical modelling and numerical simulation of electric circuits and semiconductor devices. At the second Oberwolfach conference devoted to this important and timely field, scientists from around the world, mainly applied mathematicians and electrical engineers from industry and universities, presented their new results. Their contributions, forming the body of this work, cover electric circuit simulation, device simulation and process simulation. Discussions on experiences with standard software packages and improvements of such packages are included. In the semiconductor area special lectures were given on new modelling approaches, numerical techniques and existence and uniqueness results. In this connection, mention is made, for example, of mixed finite element methods, an extension of the Baliga-Patankar technique for a three dimensional simulation, and the connection between semiconductor equations and the Boltzmann equations.

The Taylor-Couette system is one of the most studied examples of fluid flow exhibiting the spontaneous formation of dynamical structures. In this book, the variety of time independent solutions with periodic spatial structure is numerically investigated by solution of the Navier-Stokes equations.