Vol.2, No 8, 1998 pp. 783 - 788
UDC: 531
A REVIEW OF THE THIRD INTERNATIONAL CONFERENCE
ON NONLINEAR MECHANICS - ICNM-III
Katica (Stevanović) Hedrih
Faculty of Mechanical Engineering, University of Niš
e-mail: katica@masfak.masfak.ni.ac.yu
Abstract. The article provides the basic scientific-professional information
about the organizer and the program of The Third International Conference
on Nonlinear Mechanics - ICNM-III, August 17-20, 1998 at the Shanghai University,
China, as well as about its participants. It also presents a review of
the given General Lectures and the given short lectures during the Conference,
as well as a survey of the directions of futher research in the field of
nonlinear mechanics.
1. INTRODUCTION
The Third International Conference on Nonlinear Mechanics was held in the
period August 17-20, 1998. in the Shanghai University, China. It was organized
by the Shanghai University (and sponsored by Chinese Society of Theoretical
and Applied Mechanics, Municipal Commission of Science and Technology of
Shanghai, as well as by National Natural Science Foundation of China, K.
C. Wong Education Fondation-Hong Kong, Shanghai Institute of Applied Mathematics
and Mechanics, Shanghai Center for Nonlinear Sciences, Lanzhou University,
Fundan University, Shanghai Jiaotong University, Tongji University, as
well as by Journal "Applied Mathematics and Mechanics"). It is the most
competent scientific conference in the field of nonlinear mechanics offering
the highest and cognitive potentials in nonlinear mechanics.
Chairman of the Steering Committe was Prof. dr Wei-Zang Chien, President
of Shanghai University. Vice-Chairmans of the Steering Committe were professors:
A. Jeffrey (UK), W. A. Nash (USA), V. V. Rumyantsev (Russia), Hao-sheng
Tan (China) and Feng-gan Zhuang (China). Members of the Steering Commitee
were from U.S.A, Hong Kong, Canada, Australia, Ukraine, France, Japan,
Germany, Poland, Holland, China, UK. Chairman of the Scientific Committe
was Prof. dr Tian-min Dai, and Vice-Chairmans of the Scientific Committe
were professors: Chang-jun Cheng, Shi-qiang Dai and Quan-shui Zheng. Chairman
of the Local Organizing Committe was professor Zhe-wei Zhou.
This specialized international conference gathered a big number of
active and most competent reserchers and scientists in the field from all
over the world (Australia, Belgium, Canada, China, France, Germany, Poland,
Hong Kong-China, Israel, Italy, Japan, Macau, Pakistan, Russia, UK, USA
and Yugoslavia).
Twenty-four General Lectures were given with duration of 40 minites
each and 152 short lectures followed by discussions and active response
of the participants resulting in the exchange of relevant scientific information,
agreements and initiatives for joint reserch projects.
The Opening Ceremony was lead by chairman of Local Organizing Committee,
Professor Zhou Zhe-wei at Lecture Hall-Shanghai University. Opening Ceremony
includes Opening Address by Chairman of Steering Committee professor Chien
Wei-zang, Congratulatory Speech by Representative of Shanghai Municipal
Government and Congratulatory Speech by Professor Zhuang Feng-gan, Chairman
of Chinese Society of Theoretical and Applied Mechanics.
The Program of the Conference continued by tree General Lectures:
A. J. M. Spencer (UK): The Thermoelastic Springback Effect for Nonlinear
Materials. Springback is an effect that occurs in processing of fibre-reinforced
plastic materials, and involves distorsion of parts formed at high temperature
when they are cooled to an ambient temperature. It is due to differential
thermal contraction in highly anisotropic materials. For channel sections,
which have single curvature, a simple analysis has been given previously
for linearly thermoelastic and thermoviscoelastic materials. This analysis
is exetended to nonlinear thermoelastic and thermoviscoelastic deformations.
T. Y. Wu (USA): Fully Nonlinear Water Waves. An expository review is
given on a theory of modeling fully nonlinear, fully dispersive, time-evolving,
three-dimensional gravity-capillary waves on water of uniform depth. Its
relationship with some existing models will be discussed for their differing
purposes pertaining to different parametric regimes. Interesting phenomena
in various cases will be illustrated by applications of the models with
review and discussion of literature.
Zhuang Feng-Gan (China): On High Order Accuracy Schemes and the Numerical
Simulation of Some Complex Flows. The paper-lecture gives two guiding principles
in the set up of high order accuracy numerical schemes. Several numerical
schemes of high order accuracy are then suggested. after a strict test
for some typical shock problems, the schemes with or without modifications
are applied to study the supersonic reacting mixing layer and illustrate
supersonic swirl and shock waves in enhancing the mixing of two different
gases.
Conference Program of the first working day continued by eight Parallel
General Lectures:
S. S. Antman (USA): The Crutial Role of Viscous Damping in Solid Mechanics.
This paper describes several problems of solid mechanics whose analysis
depends crucially on the specific nature of viscous dissipative stresses.
Purely longitudinal motions of a viscoelastic rod. Spatial motion of a
viscoelastic rod. Shearing oscillations of a viscoelastic layer. Other
nonconservative problems.
Chen Zhi-Da (China): Nonlinear Contact Mechanics and Fracture of Plate
under Impulsive Load. Contact Problem is the most challenge and attractive
part of mechanics since Hertz. As the contact interface, the pressure and
contact area are unknown apriori, at the same time, there always occur
large deformation and large local rotation at the contact points, the classical
theory of linear elasticity can not solve the contact points. The paper-lecture,
it is shown that in the case of large plastic deformation of a circular
plate under impulsive load of a rigid ball, the non-Kirchhoff-Love plate
theory of Prof. Chien, coupled with nonlinear contact mechanics should
be used in solving the problem.
A. D. Drozdov (Israel): Constitutive Models for the Nonlinear Viscoelastic
Response of Solid Polymers with Mechanically Induced Material Clocks. The
paper-lecture presents a review of constitutive equations for the nonlinear
viscoelastic response of solid polymers under isothermal loading with finite
strains. It focuses on materials which do not posses the separability property.
C. S. Man (USA): Material Tensors of Weakly-Textured Polycrystals.
Material tensors to polycrystalline aggregates should also manifest the
influence of crystallographic texture on the material properties in question.
In this paper we consider weakly-textured polycrystals and outline a procedure
by which the quantitative effects of texture on material tensors can be
delineated explicitly. This procedure is based physically on an assumption
motivated by the general principles of material frame-influence and isotropy
of space. It employs mathematical tools from the theory of group representattions
and theory of invariants.
Henri Cabannes (France): Proof of the Conjecture on "Eternal" Positive
Solutions for a Model of the Boltzmann Equation. According to a classical
conjecture, the only positive "eternal" solutions of the Boltzman equation
are the maxwellian solutions. Author proves this conjecture in the case
of a related equation, which is a semi-continuous model of the two-dimensional
homogeneous Boltzmann equation.
W. H. Hui (Hong-Kong): A Unified Coordinate System for Computting Discontinu-ous
Flows.
Li Jia-chun and Xie Zheng-Tong (China): Subgrid Scale Model in Large
Eddy Simulation. The current paper-lecture presents an overview on the
present state of the arts in LES of turbulence, especially with stress
on subgrid scale models, which appear fundamental to LES. A new SGS model
suggested by authors is proved superb to the previous ones when applied
in the simulation of turbulence in and over canopy as illustration. LES
will become a most promising approach for industry design and enviromental
prediction at the begining of the next century while RANS and DNS remain
complementary tools in the study of tubulence.
K. (Stevanović) Hedrih (Yugoslavia): Vectorial Method of the Kinetic
Parameter Analysis of the Rotor with Many Axes and Nonlinear Dynamics.
By using examples of the rotor system which rotates about two axes with
section or without section, we build the vectorial method of the kinetic
parameters analysis of the rotors with many axes. The vectors connected
for the pole and the axis are used for the analysis of kinetic parameters,
by the use of which the rotation properties of the mass configurations
are interpreted introducing the mass moment vectors for the pole and the
axis, as well as the kinematic vectors rotators. Expressions for the corresponding
linear momentum and angular momentum, as well as their derivatives in time
are derived. By these expressions vectorial equations of the rotor system
dynamics are derived, as well as the expression for the kinetic pressures
on the rotor system bearings.
By using vectorial equations, we composed two scalar differential equations
of the heavy rotor system nonlinear dynamic. For the case when one rotation
about axis is controlled by constant angular velocity the nonlinear dynamics
of the rotation about other axis is studied. Nonlinear rotor system dynamics
are presented by phase portrait in the phase plane, with trigger of the
singularities, as well as with homoclinic orbits and homoclinic points
of the nonstable type saddle. For the case rotor system dynamics under
the action of the perturbed couple the sensitive dependence in the vicinity
of the equilibrium nonstable position which corresponds to homoclinic point
of the type nonstable saddle, the possibility of the chaotic character
behavior is pointed out.
Next working days, the Programm of the Conference contained following
sections: Solid Mechanics, Fluid Mechanics, Nonlinear Dynamics, Mathematical
Methods in Mechanics, Solid Mechanics.
Last working day the Program of the Conference contained the following
Parallel General Lectures:
Yang Gui-Tong (China): Nonlinear Strain Waves in Solids. The lecture
presents some phenomena of nonlinear wawes in solids. Several kinds of
effects of nonlinear are reviewed.
Zheng Quan-Shui and T. Chen (China): Invariance Shifts and Reduced
Dependence in Electro-Magnetic Elastic Fibrous Materials with Defects.
In generalized plane electromagnetic elasticity involving a fibrous material
with defects, the stress, electric displacement and magnetic induction
states may be invariant upon some shifts, the invariance shifts, in the
electromagnetic moduli. The present article derives the complete set of
the invariance shifts. As an application of the invariance shifts, it is
proved that the incremental moduli between the overal and the matrix ones
for a multiphase composite with defects depend only on a reduced list of
the moduli of the matrix and the inclusions.
Liu Yan-Zhu and Chen Li-Qun (China): Nonlinear Problems in Spacecraft
Attitude Dynamics. This lecture presents a reviw of some nonlinear problems
in spacecraft attitude dynamics. The resutls on attitude stability of multibody
spacecraft, spacecraft with flexible bodies, and spacecraft containing
liquid are summarized. The progress in studying bifurcations and chaos
of spacecraft attitude motions is surveyed. Some promising directions for
further research are proposed.
Xu Jian-Xue (China): On the Nonlinear Parametric Excitation Problems
in the Engineering. In this lecture, the nonlinear parametric excitation
problems of a one and a half degree of freedom system describing the dynamics
problem of an electromagnetic mechanical coupled system, axial vibration
of transformer during ampere-turn unequilibrium and others are studied,
some special problems are presented.
Last working day the Program of the Conference contained the following
General Lectures:
R. Grimshaw (Australia): Internal Solitary Waves in the Atmoshere and
Ocean. Author gives a brief account of the basic theory of internal solitary
waves with the emphasis on application to observations in the atmosphere
and ocean. Starting with the equations of motion for an inviscid incompressible
fluid, author indicates how various asymptotic models for weakly nonlinear
long waves are derived, including the well-known Korteweg-de Vries equation.
Author then describes the solitary wave solutions, and relate their properties
to observations. Various generalizations are considered which inter alia
take into account the variable background environment.
L Ting (USA): Notes on the Dynamics of Vortex Filaments and Their Core
Structure. Author give a brief of the asymptotic theory of slender vortex
filaments with emphases on i) the choices of scalings and small parameters
characterizing the physical problem; ii) the kay steps in the formulation
of the theory and iii) the assumptions and/or restrictions on the theory
of Callegari and Ting (1978). Author present highlists of an extension
of the 1978 asymptotic theory: the analyses for core structures with axial
variation. Making use of the physical insight gained from the analysis,
we present a new derivation of the evolution equations for the core structure.
The one is simpler and straight forward and shows the physics clearly.
A. Jaffrey (UK): Techniques for Studying Nonlinear Wave Equation. This
lecture reviews some of the mathematical techniques that can be used both
for the determination of general properties of solutions of nonlinear wave
equations and also for their explicit solution. Burgers equation without
dissipation and a generalization. Shock solutions. Traveling wave solutions
and solitons. Self-similar solutions and group theoretic methods. Reductive
perturbation method and a generalization. Baclund transformations.
Jan Rychlewski (Poland): Elastic Waves under an Unusual Anisotropy.
Zhou Heng (China): Why K-B Method in Nonlinear Mechanics Usually Does
Not Yield Convergent Solution (As See From its Application in the Theory
of Hydrodynamic Stability). Krylov-Bogolubov method is one of the few general
methods in nonlinear mechanics and is widely applied. However, it usually
does not yield a convergent solution. Author will show why it is so by
analyzing a prototype problem in its application in the theory of hydromagnetic
stability. Ways of its improvements will also be given. The concept is
equally applicable to other problems.
V. V. Rumyantsev (Russia): On General Equations Analytical Dynamics.
The paper-lecture presents an introduction in the theory of the generalized
Poincaré's and Chetayev's equations based on a closed system of infinitesimal
operators. These equations include both the motion's equations in independent
and dependent, holonomic and nonholonomic coordinates for holonomic mechanical
systems with finitenumber of degree of freedom. In this sence the generalized
Poincaré-Chetayev's equations are the general equations of analytical dynamics.
Some examples are considered.
The participation on such a scientific conference offers an outstanding
experiance and scientific satisfaction, providing grounds for the comparison
of one's own scientific results with the results of other researchers and
their evaluation, which is always an inspiration for new scientific projects.
The attitudes of the colleagues shared on such occasions are also a unique
scientific inspiration; on the other hand, new ideas ease and smooth the
way for keeping up with the latest achievements in the field - nonlinear
mechanics.
The organizers of the ICNM - III presented following publications:
Final Program and List of Participants, pp. 27, and Proceedings of the
3rd International Conference on Nonlinearn Mechanics, edited by Prof. dr
Chien Wei-Zang, pp. 884 + 8+4.
The proceedings collects 176 papers accepted for the presentation on
the 3rd International Conference on Nonlinearn Mechanics, which was held
in Shanghai, a continuation of the two previous ICNMs held in 1985 and
1993. In the Preface of this proceedings Professor Chien Wei-Zang, Chairman
of the Steering Committee wrote: "Nonlinear mechanics is a subject of great
importance in the development of science and technology. The aim of the
conference is to provide a forum to exibit the progress in this field during
the past five years and a place to further the interaction of modern mathematics
and modern mechanics. Compared with the first two proceedings, this one
shows more profoundinsight into the essentials of nonlinear mechanics.
It is worthy mentioning that 24 renowned scholars will present a variety
of significant topics in the area, which will certainly enlighten the meeting
a great deal".
In the same Preface Professor Chien Wei-Zang pointed out the following:
"This series of Conference have been concerned and supported by the specialists
in nonlinear mechanics all over the world, in particular, the member of
Steering Committee and Scientific Committee. All the participants knew
that among them, Professor Guo Zhongheng played a crucial role in organizing
the first two conferences. Unfortunately, on September 22, 1993, that is,
less than one month after the ending of the ICNM-II, Professor Guo Zhongheng
passed away. On this occasion, I would like to express my profound mourning
for him. I belive that all of his friends and students will remember his
remarcable contribution to nonlinear mechanics and to our Conferences,
and also his perfect personality".
REFERENCES
1. Final Program and List of Participants, Shanghai University Press,
pp. 27.
2. Proceedings of the 3rd International Conference on Nonlinearn
Mechanics, edited by Prof. dr Chien Wei-Zang, Shanghai
University Press, pp. 884 + 8+4.
PRIKAZ TREĆE INTERNACIONALNE KONFERENCIJE
NELINEARNE MEHANIKE ICNM-III
Člankom se daju naučno-stručne informacije o organizatorima i naučnom programu
Treće internacionalne konferencije nelinearne mehanike ICNM-III održane
u avgustu, od 17 do 20 1998 na Univerzitetu u Šangaju, Kina, kao i o učesnicima.
Dati su apstrakti plenarnih predavanja, kao i izabranih saopštenja. Date
su informacije o sekcijama u kojima je konferencija radila.
