Nonlinear Systems
Mostrando 13-24 de 557 artigos, teses e dissertações.
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13. Modeling the individual height and volume of two integrated crop-livestock-forest systems of Eucalyptus spp. in the Brazilian Savannah
ABSTRACT. The aim of this study was to model the individual height and volume of eucalyptus wood in two integrated crop-livestock-forest systems (ICLF1 and ICLF2) in Campo Grande, a city in the state of Mato Grosso do Sul, Brazil. Classic nonlinear growth models were adjusted for height (Logistic, Gompertz, Richards, Weibull, Van Bertalanffy, Brody, Mitscher
Acta Sci., Agron.. Publicado em: 28/03/2019
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14. ON AN INTEGRATED DYNAMIC CHARACTERIZATION OF VISCOELASTIC MATERIALS BY FRACTIONAL DERIVATIVE AND GHM MODELS
Abstract The passive vibration control of mechanical systems under unwanted vibrations can be accomplished in a very effective way by using devices incorporating viscoelastic materials. The design of such devices requires a broad knowledge of the dynamic properties of the employed viscoelastic material, usually supplied by adequate mathematical models. Among
Lat. Am. j. solids struct.. Publicado em: 14/03/2019
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15. Extremum Seeking-based Adaptive PID Control applied to Neuromuscular Electrical Stimulation
Abstract A multivariable deterministic extremum seeking (ES) is being evaluated to construct an adaptive Proportional-Integral-Derivative (PID) control law for the functional Neuromuscular Electrical Stimulation (NMES) of stroke patients. The developed scheme is applied to control the position of the patient’s arm so that movements of flexion/extension for
An. Acad. Bras. Ciênc.. Publicado em: 14/02/2019
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16. Strut-and-tie models for linear and nonlinear behavior of concrete based on topological evolutionary structure optimization (ESO)
Resumo A busca por sistemas resistentes representativos para estrutura de concreto requer profundo conhecimento sobre seu comportamento mecânico. Os modelos de bielas e tirantes são procedimentos clássicos utilizados no dimensionamento do concreto armado onde existem concentrações de tensão, as chamadas regiões descontínuas da estrutura. No entanto,
Rev. IBRACON Estrut. Mater.. Publicado em: 2019-02
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17. Simple but accurate periodic solutions for the nonlinear pendulum equation
Abstract Despite its elementary structure, the simple pendulum oscillations are described by a nonlinear differential equation whose exact solution for the angular displacement from vertical as a function of time cannot be expressed in terms of an elementary function, so either a numerical treatment or some analytical approximation is ultimately demanded. Su
Rev. Bras. Ensino Fís.. Publicado em: 21/09/2018
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18. Critical analyses when modeling tree biomass to ensure additivity of its components
ABSTRACT It is presented the theme additivity of biomass of tree components. To evaluate and discuss this context, experimental information collected in forests of Acacia mearnsii De Wild. was used. Equations for components (stem and crown) and total biomass were fitted by means of two procedures: 1) generalized nonlinear least squares and 2) weighted-nonlin
An. Acad. Bras. Ciênc.. Publicado em: 17/05/2018
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19. On the Nonlinear Transient Analysis of Planar Steel Frames with Semi-Rigid Connections: From Fundamentals to Algorithms and Numerical Studies
Abstract This paper presents the fundamentals for prediction of a more realistic behavior of planar steel frames with semi-rigid connections under dynamic loading. The majority of the research in this area concentrates on the nonlinear static analysis of frames with semi-rigid connections. Indeed, few studies have contributed to the nonlinear dynamic and vi
Lat. Am. j. solids struct.. Publicado em: 03/05/2018
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20. Numerical analysis of truss systems with stiffened flattened end-bars
Abstract Circular hollow sections are usually used in long-span roof truss systems. One of the typology for connecting elements in such structures involves the flattening of bar ends. This article presents the numerical analysis of a plane truss composed of circular hollow sections, in which diagonal bars have flattened ends. In this sense, a new flattening
Lat. Am. j. solids struct.. Publicado em: 03/05/2018
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21. Modeling the creep behavior of GRFP truss structures with Positional Finite Element Method
Abstract This paper presents the development of a formulation, based on Positional Finite Element Method, to describe the viscoelastic mechanical behavior of space trusses. The numerical method used was chosen due to its efficiency in the applications concerning nonlinear numerical analyses. The formulation describes the positional variation over time under
Lat. Am. j. solids struct.. Publicado em: 26/04/2018
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22. Run time Assessment for Gas Turbine Performance Simulation
ABSTRACT: This article describes the run time characteristics of a gas turbine performance simulation using different solvers and components off-design performance database formats. Two different nonlinear systems of equation solvers, Newton-Raphson's and Broyden's, and two different formats of compressor and turbine off-design performance database (maps), t
J. Aerosp. Technol. Manag.. Publicado em: 15/03/2018
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23. Distortional Failure and DSM Design of Cold-Formed Steel S-Shaped Beams Under Uniform Bending
Abstract This work reports a numerical investigation on the distortional buckling/post-buckling behaviors, ultimate strength and Direct Strength Method (DSM) design of cold-formed steel S-beams, commonly used in industrial rack systems. The analyzed beams are single-span, under uniform bending, exhibiting two different end support conditions and 5 cross-sect
Lat. Am. j. solids struct.. Publicado em: 2017-12
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24. Growth and yield models for eucalyptus stands obtained by differential equations
ABSTRACT: The main purpose of this study was to assess nonlinear models generated by integrating the basal area growth rate to estimate the growth and yield of forest stands. The database was collected from permanent sample units, in Paraopeba county, in the state of Minas Gerais, Brazil. The stands were represented by Eucalyptus camaldulensis × Eucalyptus
Sci. agric. (Piracicaba, Braz.). Publicado em: 2017-10