[NotiAMCA] Uncertainties in Nonlinear Structural Dynamics

Mie Mayo 9 11:11:18 ART 2007

INFORMATIVO ABCM Nº 050/07 – Uncertainties in Nonlinear Structural Dynamics

Fonte: José Manuel Balthazar (UNESP/FEG)

 Uncertainties in Nonlinear Structural Dynamics

Call for Papers

Nonlinear dynamical systems usually display high complexity. The last
decades hasseen a remarkable and fruitful development of nonlinear
dynamics and a large number of papers have been published in all branches
of science.

In modeling natural and man-made systems, it is assumed in general that
the systems perfect and that all parameters of the system are known.
However, real systemsare usually imperfect and uncertainties are present
both in system parameters and inthe modeling stage. This is associated
with the lack of precise knowledge of thesystem parameters, random or
noisy external loading, operating conditions andvariability in
manufacturing processes, among other things. In many situations,
theseuncertainties are not important and may be overlooked in the
mathematical modelingof the problem. However, in several situations, the
uncertainties can have significantinfluence on the dynamic response and
the stability of the system.

Uncertainties may also be found in system response, even in cases where
allparameters are well established, such systems exhibiting high
sensitivity to initialconditions.

This is particularly important in strongly nonlinear chaotic systems and
those withfractal-basin boundaries.

Also, in many systems, unexpected interactions between different parts of
thesystems such as in nonideal problems may lead to complex responses.

However, the influence of uncertainties on local and global bifurcations
and basins ofattractions and on important engineering concepts such as
reliability, safety, androbustness is not well studied in literature.

Even the definition of a random bifurcation is still an open problem in
nonlineardynamics.

This is a rather broad topic in nonlinear dynamics. So, the present
special issue willbe dedicated to the influence of uncertainties on
structural dynamics (beams, plates,shells, frames, etc.). In these
structures, the main sources of uncertainties are:

    * Imperfections.
    * Uncertainties in system parameters (mass, damping, and stiffness).
    * Uncertainties in the external load, such as random loads (wind,
earthquake,etc.)
    * Sensitivity to initial conditions.
    * Interaction between load and structure.

These types of uncertainties coupled to system nonlinearities may have a
markedinfluence on the structure's response, particularly in a dynamic
environment.

So it is useful to study their influence on bifurcations, stability
boundaries, and basinsof attraction.

It is also interesting to discuss their influence on safety factors,
integrity measures,and confiability.

These topics are essential for a safe design of structures and the
development ofmathematically based safe (but not too conservative) design
codes andmethodologies. Since structural systems may be studied using both
continuous anddiscretized models, problems involving PDEs and ODEs should
be considered.There is a large scientific community working on nonlinear
dynamics of structuresthat may contribute to this special issue.

Authors should follow the Mathematical Problems in Engineering manuscript
format described at the journal site http://www.hindawi.com/journals/mpe/.
Prospective authors should submit an electronic copy of their complete
manuscript through the journal's Manuscript Tracking System at
http://www.hindawi.com/mts/, according to the following timetable.

Manuscript Due

October 1, 2007

First Round of Reviews

January 1, 2008

Publication Date

April 1, 2008

Guest Editors:

José Manoel Balthazar, Department of Statistics, Applied Mathematics
andComputation, State University of Sao Paulo at Rio Claro(UNESP),
13500-230 Rio Claro, SP, Brazil

Paulo Batista Gonçalves, Civil Engineering Department, Catholic University
(PUC-Rio), 22453-900 Rio de Janeiro, RJ, Brazil

Reyolando M. R. L. F. Brasil, Department of Structural and Geotechnical
Engineering, Polytechnic School, The University of Säo Paulo
(PEF/EPUSP/USP) 05508-900 Säo Paulo, SP,Brazil

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