Iutam Symposium On Creep In Structures

These proceedings contain 48 innovative papers consolidating the development of creep research since 1990 and discussing the new horizons in this fundamental field of applied mechanics in the coming century. This volume is useful for researchers and graduate course students in the relevant fields.

This book offers a current state of the art in analysis and modeling of creep phenomena with applications to the structural mechanics. It presents the some presentations from the IUTAM-Symposium series "Creep in Structures", which held in Magdeburg (Germany) in September 2023, and it discusses many advances and new results in the field. These are for example: interlinks of mechanics with materials science in multi-scale analysis of deformation and damage mechanisms over a wide range of stresses and temperature; development and analysis of new alloys for (ultra)high-temperature applications; formulation and calibration of advanced constitutive models of inelastic behavior under transient loading and temperature conditions; development of efficient procedures and machine learning techniques for identification of material parameters in advanced constitutive laws; introduction of gradient-enhanced and non-local theories to account for damage and fracture processes; and application of new experimental methods, such as digital image correlation, for the analysis of inelastic deformation under multi-axial stress state.

There is a tradition to organize IUTAM Symposia "Creep in Structures" every ten years: the first Symposium was organized by N.J. Hoff in Stan ford (1960), the second one by J. Hult in Goteborg (1970), and the third one by A.R.S. Ponter in Leicester (1980). The fourth Symposium in Cracow, September 1990, gathered 123 par ticipants from 21 countries and reflected rapid development of the theory, experimental research and structural applications of creep and viscoplas ticity, including damage and rupture. Indeed, the scope of the Sympo sium was broad, maybe even too broad, but it was kept according to the tradition. Probably the chairman of "Creep in Structures V" in the year 2000 (if organized at all) will be forced to confine the scope substantially. Participation in the Symposium was reserved for invited participants, suggested by members of the Scientific Committee. Total number of sug gestions was very large and the response - unexpectedly high. Apart from several papers rejected, as being out of scope, over 100 papers were accepted for presentation. A somewhat unconventional way of presenta tion was introduced to provide ample time for fruitful and well prepared discussions: besides general lectures (30 minutes each), all the remain ing papers were presented as short introductory lectures (10 minutes) followed by a I-hour poster discussion with the authors and then by a general discussion. Such an approach made it possible to present general ideas orally, and then to discuss all the papers through and through.

There is a tradition to organize IUTAM Symposia "Creep in Structures" every ten years: the first Symposium was organized by N.J. Hoff in Stan ford (1960), the second one by J. Hult in Goteborg (1970), and the third one by A.R.S. Ponter in Leicester (1980). The fourth Symposium in Cracow, September 1990, gathered 123 par ticipants from 21 countries and reflected rapid development of the theory, experimental research and structural applications of creep and viscoplas ticity, including damage and rupture. Indeed, the scope of the Sympo sium was broad, maybe even too broad, but it was kept according to the tradition. Probably the chairman of "Creep in Structures V" in the year 2000 (if organized at all) will be forced to confine the scope substantially. Participation in the Symposium was reserved for invited participants, suggested by members of the Scientific Committee. Total number of sug gestions was very large and the response - unexpectedly high. Apart from several papers rejected, as being out of scope, over 100 papers were accepted for presentation. A somewhat unconventional way of presenta tion was introduced to provide ample time for fruitful and well prepared discussions: besides general lectures (30 minutes each), all the remain ing papers were presented as short introductory lectures (10 minutes) followed by a I-hour poster discussion with the authors and then by a general discussion. Such an approach made it possible to present general ideas orally, and then to discuss all the papers through and through.

This volume constitutes the Proceedings of the IUTAM Symposium on "Analytical and Computational Fracture Mechanics of Non-homogeneous Materials", held in Cardiff from 18th to 22nd June 2001. The Symposium was convened to address and place on record topical issues in analytical and computational aspects of the fracture of non-homogeneous materials as they are approached by specialists in mechanics, materials science and related fields. The expertise represented in the Symposium was accordingly very wide, and many of the world's greatest authorities in their respective fields participated. Given the extensive range and scale of non-homogeneous materials, it had to be focussed to enhance the quality and impact of the Symposium. The range of non-homogeneous materials was limited to those that are inhomogeneous at the macroscopic level and/or exhibit strain softening. The issues of micro to macro scaling were not excluded even within this restricted range which covered materials such as rock, concrete, ceramics and composites on the one hand, and, on the other, those metallic materials whose ductile fracture is strongly influenced by the presence of inhomogeneities. The Symposium remained focussed on fundamental research issues of practical significance. These issues have many common features among seemingly disparate non-homogeneous materials.

The first IUTAM Symposium on Creep in Structures was held in Stanford, Cal. 1960 (Proceedings, ed. N. J. HOFF, Springer-Verlag 1962). That meeting reflected an intense research activity in the field of structural creep, and many important results were pre sented. In spite of this progress design rules for high temperature equipment are still often inadequate. Design against creep deformation and creep rupture is all too often based only oli experience and intuition. With technological processes moving into ever higher temperature regions the effects of creep must be given steadily increasing attention. The IUTAM Bureau in 1967 decided to arrange a Second Symposium on Creep in Structures, to be held in Gothenburg under the chairmanship of F. K. G. ODQVIST. This meeting was to take stock of the progress made in the ten years since the first symposium. Notable advances in the establishment of a sound phenomenological theory, refined experimental techniques and several new methods of structural analysis of shells in the creep range gave impetus to this second symposium. Problems of rupture and stability under complex loads had been studied and many new results in these fields were presented and discussed. Attendance was strictly limited to persons active in the field covered by the symposium. Financial support was generously provided by IUTAM, Chalmers University, the Swedish Board for Technical Develonment and four Swedish industrial companies (ASEA, Sand mens Jernverk, Saab-Scania, Volvo).

The Third IUTAM Symposium on Creep in Structures was held at Leicester University in September 1980 thereby continuing the tradition of a ten yearly review of progress in structural creep initiated by the previous symposia held at Stanford University in 1960 and Chalmers University in 1970. The thirty eight papers and their discussions cont ained in this volume testify to the vigour of research into the creep of structures at the present time. During the last ten years a gradual change of emphasis has occurred in creep research from studies of deformation and stability towards the description of continuum damage and creep crack propagation. At the same time design techniques have developed based upon reference stress techniques and bounding theorems, and a continued interest has been maintained in the development of constitutive equations and in stability studies. All these developments are reflected in the compos ition of the papers in the volume and in the discussions and reviews.