Q.S. Nguyen - Böcker

This proceedings volume contains 39 papers presented at the IUTAM Sym- posium on Variations of Domains and Free Boundary Problems in Solid Mechanics, held in Paris from April 22nd to 25th 1997, at the Ecole des Mines and the Ecole Poly technique. This symposium offered an opportunity for researchers from all engineering disciplines and applied mathematics to review the state of the art and to identify new trends and new features in the field. Mechanical modelling, mathematical discussion and numerical resolution have been the primary goals of the meeting. Principal subjects of discussion concerned ground freezing, shape memory alloys, crystal growth, phase change in solids, piezo-electricity, wavelets, delamination, damage, fracture mechanics, polymerization, adhesion, fric- tion, porous media, nucleation, plasticity, inverse problems, and topological optimization. More than 80 scientists of different nationalities participated in this sym- posium. Efforts of many people made this symposium possible. We would like to thank all the authors and participants for their contributions and the members of the Scientific Committee for their patronage and assistance in selecting papers.The effectiveness of the Organizing Committee is ac- knowledged. We are pleased to thank all the involved members of the two Laboratories : Laboratoire de Mecanique des Solides and Laboratoire des Materiaux et des Structures du Genie Civil, specially Valerie Fran

The first theme concerns the plastic buckling of structures in the spirit of Hill's classical approach. Non-bifurcation and stability criteria are introduced and post-bifurcation analysis performed by asymptotic development method in relation with Hutchinson's work. Some recent results on the generalized standard model are given and their connection to Hill's general formulation is presented. Instability phenomena of inelastic flow processes such as strain localization and necking are discussed. The second theme concerns stability and bifurcation problems in internally damaged or cracked solids. In brittle fracture or brittle damage, the evolution law of crack lengths or damage parameters is time-independent like in plasticity and leads to a similar mathematical description of the quasi-static evolution. Stability and non-bifurcation criteria in the sense of Hill can be again obtained from the discussion of the rate response.