Mini-Symposium

F. Stochastic Modeling and Uncertainties in Solid Mechanics

This symposium aims at bringing together researchers and engineers addressing the treatment of uncertainties in Applied Mechanics. Uncertainties due to either incomplete or lack of information and due to inherent randomness of natural phenomena affects the response and performance of most mechanical and structural systems. A consequence of uncertainty is the possibility of undesirable system response or undesirable system performance (failure).

Structural reliability analysis addresses the quantification of failure probabilities. Risk analysis encompasses the evaluation of failure probabilities and quantification of failure consequences.
Stochastic mechanics involves the explicit modeling of the propagation of uncertainties through mechanical and structural systems. Loading conditions, material properties, and geometry are significant sources of uncertainty. Statistical and probabilistic procedures provide a sound framework and a rational basis for dealing with these uncertainties. In addition to parameter uncertainties, model uncertainties also play a significant role in modern structural mechanics. In reality, neither the true model nor the model parameters are deterministically known. For model uncertainties in particular, the assumption that an ever finer discretization leads to an increase in accuracy is a myth. In this context, the aspects of model validation and verification also have to be addressed.

The main aim of this symposium is to discuss conceptual and computational aspects of uncertainty assessment in Applied Mechanics.

Papers that address the following topics are appropriate for this symposium:

1. modeling of uncertainty via probabilistic or non-probabilistic methods;
2. incorporation of uncertainty in mechanical modeling;
3. stochastic mechanics;
4. stochastic finite element method;
5. random vibration and stochastic dynamics;
6. reliability analysis of mechanical and structural systems;
7. risk analysis;
8. decision making in the presence of uncertainty;
9. reliability-based design optimization;
10. robustness of mechanical systems under uncertainty;
11. fatigue reliability.

Support: ABCM Stochastic Mechanics Committee.

Symposium coordinators:

Prof. Rubens Sampaio, Ph.D.	Prof. André T. Beck, Ph.D.
Departamento de Eng. Mecânica	Departamento de Engenharia de Estruturas
PUC-Rio	Escola de Engenharia de São Carlos
Rua Marquês de São Vicente, 225	Universidade de São Paulo
22453-900 Rio de Janeiro RJ, Brazil	Av. Trabalhador Sãocarlense, 400
	13566-590 São Carlos, SP, Brazil
Tel: 55-21-35271172	Phone: 55-16-3373 9460
Fax: 55-21-35271165	Fax: 55-16-3373 9482
Prof. Hector Jensen, Ph.D.	Prof. Edson Cataldo, D. Sc.
Department of Civil Engineering	Applied Mathematics Department
Santa Maria University	Universidade Federal Fluminense
Av. España 1680, Casilla 110-V	Graduate Program in Telecommunications in Engineering
Valparaiso, Chile	Rua Mário Santos Braga, S/N, Centro
Phone: 56-32-2654383	Niterói, CEP: 24020-140, RJ, Brazil
Fax: 56-32-2654115

 

INVITED LECTURE

A CONSPECTUS OF MODERN STOCHASTIC MECHANICS THEMES

POL D. SPANOS
Ryon Chair of Engineering
Rice University, Houston ,USA

 

ABSTRACT.A presentation of methods which are currently used in stochastic mechanics applications will be attempted. Particular attenti on will be devoted to methods, such as equivalent linearization and equivalent quadratization, for random response determination of nonlinear dynamic systems. Furthermore, efficient methods for the simulation of multi-variate and multi-dimensional stochastic processes using digital filters in the context of Monte Carlo analyses will be discussed. Appended to this theme will be a recent stochastic solution to the problem of synthesizing time histories compatible with a described shock spectrum commonly prescribed in dynamic applications. Also, approaches for determining the stochastic response of nonlinear systems involving terms with fractional derivatives will be presented. Finally, the option of capturing localized temporal and spatial effects in dynamic system responses via the family of harmonic wavelets will be discussed. Examples from the fields of material engineering, earthquake engineering, wind engineering, and off shore engineering will be presented.

Acknowledgement. This lecture was made possible through financial support from Fundação de Apoio à Pesquisa do Estado de São Paulo (FAPESP), Coordination for the Improvement of Higher Education Personnel (CAPES), and National Council for Scientific and Technological Development (CNPq).