PREFACE

The Proceedings of the Abstracts contain 25 abstracts of Invited Plenary Lectures and  77 abstracts of Short Contributed Lectures accepted for presentation at the Sixth International Symposium on Nonlinear Mechanics, Nonlinear Sciences and Applications, Niš 2003 (The 6^th ISNM  NSA NI["2003), to be held in Ni[ , Serbia and Montenegro (Yugoslavia) August 24-29, 2003.

The Sixth ISNM  NSA NI["2003 is a continuation of the following symposiums and conferences: The First Symposium on Nonlinear Dynamics 1983.,  Arandjelovac, 23-25 November 1983; First Yugoslav Conference on Nonlinear Deterministic and Stochastic Processes in Dynamical Systems with Applications YCNP Ni["91, August 27-30,1991 at  the Faculty of Mechanical Engineering University of Ni[, as well as of two  Minisymposiusms on Nonlinear Mechanics under the patronage of Yugoslav Society of Mechanics,  XXII and XIII Yugoslav Congress on Theoretical and Applied Mechanics Ni["95 and Vrnjacka Banja" 97. and the Fifth Yugoslav Symposium on Nonlinear Mechanics – Nonlinear Sciences at the Threshold of the Third Millennium  (YUSNM NI["2000) Ni{, October 2-5, 2000.

Academician Yuri Alekseevich Mitropolskiy, a prominent scientist, who is  well known  all over the world and who gave outstanding contribution to nonlinear mechanics, gave a General Lecture entitled "Adiabatic Processes in Nonlinear Oscillatory Systems". Academician Mitropolskiy was a distinguished guest of the Faculty of Mechanical Engineering, University of Ni[ at that Symposium and was the only participant from abroad..

The Chairman of the Organizing Committee of this first Symposium was K. (Stevanovic) Hedrih, and she gave a Contributed Lecture entitled  "Asymptotic Solution of the equations of nonlinear oscillations of thin elastic shells with positive Gauss"s curvature in two-frequency regime".

Among 32 contributed lectures at the First Symposium on Nonlinear Dynamics Arandjelovac"83 nine were given by scientist working at the Faculty of Mechanical Engineering, University of Ni[.

                The First Yugoslav Conference on Nonlinear Deterministic and Stochastic Processes in Dynamical Systems with Applications YCNP Ni["91, was held from August 27-30,1991 at  the Faculty of Mechanical Engineering University of Ni[. Proceedings - Abstracts of Lecture contain the abstracts of Invited Lectures written by prominent Scientists: Vladan Djordjevic (YU), William Nash (USA, Editor in Chief, at present Editor Emeritus, of a famous and well-known international Journal Nonlinear Mechanics, published by Pergamon Press), who took part in the Conference, Kazuyuki Yagasaki (Japan, a young scientist with significant scientific results) and others.

                Academician Yu. A, Mitropolski was the invited participant with the Plenary Lecture at  the XXII Yugoslav Congress on Theoretical and Applied Mechanics Ni["95 as well as at the Minisymposiums on Nonlinear Mechanics Ni["95. Academician Felix Chernousko, academician Anthony Kounadis and professor Guisepe Rega gave the invited Plenary Lectures at Yugoslav Minisymposiums on Nonlinear Mechanics as well.

                 It is time to remember those who initiated research on nonlinear mechanics at the Chair for mechanics and at the Faculty of Mechanical Engineering in Ni{. At the Faculty of Mechanical Engineering, Professor Danilo P. Raskovic organized the first postgraduate studies in the area of Applied Mechanics. He directed his postgraduate students towards the study of nonlinear mechanics and nonlinear oscillations. He sent his student to specialize in the fields of mathematical physics, nonlinear differential equations and nonlinear mechanics at the Institute of Mathematics of the Ukrainian Academy of Sciences, under the mentorship of the distinguished Yury Alekseevich Mitropolskiy.

Professor Danilo Raskovic, the first Head of the Chair for mechanics and academician Yuri Mitropolskiy, with their work have had permanent influence on the members  of the Chair of Mechanics at the Faculty of Mechanical Engineering in Ni[;  it, therefore, stands to reason that the Fifth International Symposium on Nonlinear Mechanics was again held in Ni[, in 2000., at the threshold of the Third Millennium. Academician Mitropolski was Chairman of the Symposium.

                During the last two decades, academician of ANS, Veljko A. Vujicic gave scientific support in the organizations of the Symposiums on Nonlinear Mechanics at the Faculty of Mechanical Engineering in Ni[.

For the last five years, academician of RAN Vladimir Matrosov and academician of RAN  V. Rumyancev, have also supported our symposiums with Lectures in the area of nonlinear mechanics. Professor Guizeppe Rega from Italy, and academician Anthony Kounadis fom Technical University Athens gave their contribution too. Academicians Nikola Hajdin, Vladan Djordjevic and  B. Vujanovic, helped to organize the previous symposiums.

Nonlinear Mechanics is a subject of great importance in the development of science and technology. The aim of the Symposium is to provide a forum to exhibit the progress in this field during the past three years and a place to further the interaction of modern mathematics and modern mechanics, as well as modern engineering sciences. The Symposium provided an extraordinary opportunity for scholars to meet and discuss recent advances in Nonlinear Mechanics. The participants represented a wide range of expertise, from pure theoreticians to people primarily oriented toward applications. A significant achievement of the Symposium were very extensive discussions taking place over the whole range from highly theoretical questions to practical engineering applications.

The main conclusion, from a total of 101 abstracts of lectures presented in this proceedings, that can be drawn is that nonlinear mechanics as  a subject has gained in extent as far as both methodology and applicability are concerned.

Professor W. Schihlen from University of Stuttgart, vice president of IUTAM, wrote: "So what is new in nonlinear dynamics and Mechanics today? The initial scope of applications in solid mechanics has broadened to cover material processing, inelasticity and fracture mechanics. In rigid body dynamics, more complex systems such as vehicles, robotics and controlled machines have come into the purview of nonlinear dynamics. On the mathematical side of nonlinear dynamics, it is now recognized that spatio-temporal problems, hysteretic and time delay problems are the new frontiers in this field. Also the term ‘complexity’ has been added to the lexicon of the chaos theory to describe the dynamics of many interacting sub-systems which can exhibit self-organization and evolution. Complexity analysis has gained a foothold in biological and some social sciences as well as in fluid and chemical physics. It remains to be seen what impact it will have in applied mechanics and engineering.

A sequence of Symposiums has been supported by scholars, dealing with Nonlinear sciences,  from Germany, Ukraine, Russia, Italy, Greece, USA, Poland, China, Austria, Romania, Bulgaria, Brazil, Czech, Slovenia.

I would here like to express my heartfelt thanks to all members of the Scientific Committee and also to the participants for their engagement in organizing of the Symposium, including the preparation of manuscripts which will be published in the University Journal Facta Universitatis, Series Mechanics, Automatic Control and Robotics, Series Mechanical Engineering and Series Civil Engineering.

Finally, on behalf of my colleagues in Serbia and Montenegro, I would like to wish all the participants of the Symposium a warm welcome.

             Katica (Stevanovi}) Hedrih,

Chairman of Organizing Committee

July 13, 2003, University of Niš