Physical Nonlinearities
Mostrando 1-12 de 14 artigos, teses e dissertações.
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1. The Equivalent Linearization Method with a Weighted Averaging for Analyzing of Nonlinear Vibrating Systems
Abstract In this paper, the Equivalent Linearization Method (ELM) with a weighted averaging, which is proposed by Anh (Anh, 2015), is applied to analyze some vibrating systems with nonlinearities. The strongly nonlinear Duffing oscillator with third, fifth, and seventh powers of the amplitude, the other strongly nonlinear oscillators and the cubic Duffing wi
Lat. Am. j. solids struct.. Publicado em: 2017-09
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2. Influence of physical and geometrical system parameters uncertainties on the nonlinear oscillations of cylindrical shells
This work investigates the influence of physical and geometrical system parameters uncertainties and excitation noise on the nonlinear vibrations and stability of simply-supported cylindrical shells. These parameters are composed of both deterministic and random terms. Donnell's non-linear shallow shell theory is used to study the non-linear vibrations of th
J. Braz. Soc. Mech. Sci. & Eng.. Publicado em: 2012
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3. The numerical modeling of thermal turbulent wall flows with the classical κ - ε model
The goal of this work is to propose a new methodology to simulate turbulent thermal wall flows using the classical κ - ε model. The focus of this approach is based on the manner used to implement heat flux boundary conditions on the solid walls. In order to explain and to validate this new algorithm, several test cases are presented, testing a great range
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2011-03
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4. Análise de criticidade de descontinuidade em um bocal de um vaso de pressão
Pressure vessels and pipes are essential equipment in the chemical, petrochemical, petroleum refining, among others. The safety operation of this equipment is an important aspect, since failures can vary from large financial losses to catastrophic consequences. Evaluation discontinuity found in inspections can be perfomed by fitness for service methodology w
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2011
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5. Operação analógica de transistores de múltiplas portas em função da temperatura. / Analog operation of multiple gate transistors as a function of the temperature.
In this work it is presented an analysis of the analog operation of multiple gate transistors, evaluating the Early Voltage, the open-loop voltage gain, the transconductance over the drain current ratio (gm/IDS), the drain conductance and, especially, the harmonic distortion exhibited by these devices. Along the work, FinFETs, Gate-All-Around (GAA) devices w
Publicado em: 2010
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6. Análise Não-Linear de Pórticos Tridimensionais Formados por Elementos Mistos de Aço e Concreto
The purpose of this dissertation is the development, implementation and test of numerical models for the Finite Element simulation of plain steel, reinforced concrete and composite steel-concrete three-dimensional frames. Physical (material) and geometrical nonlinearities are taken into account in the Finite Element formulation. At the cross section level, a
Publicado em: 2007
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7. Análise numérica do comportamento estrutural e da resistência de terças de aço restringidas pelas telhas / Numerical analysis of cold-formed purlin-sheeting systems focused on the structural behavior and strength
The structural behavior of purlin-sheeting system is complex and the complete analysis should consider the physical and geometrical nonlinearity, as well as the influence of the purlin-sheeting contact and connection. The brazilian code NBR 14762:2001 provides a design procedure to consider the interaction between a purlin or girt connected to the sheeting (
Publicado em: 2007
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8. Adaptive neural control of a class of unknown nonlinear systems.
The well-known capacity of the neural networks structures to approximate functions and nonlinear systems, to any degree of accuracy, on a compact domain, has motivated its use in actual control problems where the presence of uncertainties is inevitable. Neural networks models can be used to parameterize unknown nonlinearities, hence, the linear parameterizat
Publicado em: 2002
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9. Modelos hibridos de colunas de destilação
Techniques like online process optimization and model predictive control require fast simulations of the process models used. However, in some cases the process models are very complex or have a high dimension. In these cases acceleration techniques that include order reduction and model simplification can be used to obtain fast enough simulations. Distillat
Publicado em: 2002
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10. Aplicação do método dos elementos de contorno à análise de pavimentos de edifícios / Application of the boundary element method to slab floor analysis
This work deals with a formulation of the boundary element method applied to slab floor analysis with special emphasis concrete flat slabs exhibiting physical non-linearities. In this formulation normal and shear components of the stress tensor are taken into account to capture more accurately the ultimate strength of the structural element. The boundary ele
Publicado em: 2001
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11. Detecção e diagnostico de falhas em sistemas dinamicos utilizando redes neurais e logica nebulosa
Fault detection and diagnosis methods have been intensively studied lately, as a result of the demand for systems of greater reliability. In this work, computational intelligence methods were adopted, in a configuration that uses artificial neural networks and fuzzy logic for monitoring dynamic systems represented by state-space models of adequate dimension.
Publicado em: 1999
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12. THREE DIMENSIONAL ELASTOPLASTIC CONTACT ANALYSIS BY LARGE STRAINS / ANÁLISE ELASTO-PLÁSTICA DO PROBLEMA DE CONTATO COM GRANDES DEFORMAÇÕES EM ESTRUTURAS TRIDIMENSIONAIS
In this theses the frictionless contact problem between two- dimensional or three-dimensional deformable bodies with elasto-plastic behavior under finite strains is studied. The numeric solution procedure is based on an incremental- iterative strategy and includes the treatment of geometric and physical nonlinearities as well as those which arise from contac
Publicado em: 1998