Geometric Constraints
Mostrando 1-12 de 45 artigos, teses e dissertações.
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1. Optimization of geometrically nonlinear truss structures under dynamic loading
Abstract The goal of this article is to present the formulation of the optimization problem of truss structures with geometric nonlinearity under dynamic loads and provide examples of this problem. The formulated optimization problem aims to determine the cross-sectional area of the bars that minimizes the weight of the structure, imposing constraints on nod
REM, Int. Eng. J.. Publicado em: 2020-09
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2. Optimization of shells modeled using NURBS subjected to a dynamic loading condition
Abstract This study presents an optimization method for the thickness of shell elements subjected to dynamic loads. Structural analyses were carried out using the finite element method. The analyzed domains were modeled using NURBS, and meshes were generated using a transformation of the parametric domain into the geometric domain via a geometric function. T
REM, Int. Eng. J.. Publicado em: 2020-03
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3. Optimal design of beam-column connections of plane steel frames using the component method
Abstract This paper presents a methodology for optimization of beam-column connections of plane steel frames. The objective is to obtain beam- column connections mechanically more efficient and with minimum cost by determination of the optimal dimensions for the components of the connection; satisfying mechanical constraints associated with the bending momen
Lat. Am. j. solids struct.. Publicado em: 29/10/2018
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4. Skull shape and size variation within and between mendocinus and torquatus groups in the genus Ctenomys (Rodentia: Ctenomyidae) in chromosomal polymorphism context
Abstract We tested the association between chromosomal polymorphism and skull shape and size variation in two groups of the subterranean rodent Ctenomys. The hypothesis is based on the premise that chromosomal rearrangements in small populations, as it occurs in Ctenomys, produce reproductive isolation and allow the independent diversification of populations
Genet. Mol. Biol.. Publicado em: 2018
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5. ESTRUTURAS DE FULERENOS: ESTABELECENDO INTERFACES NO ENSINO DE MATEMÁTICA E QUÍMICA EM NÍVEL SUPERIOR
The objective of this paper is to study fullerene geometry properties and attempt to stablish a dialogue between the teaching of mathematics and chemistry concepts using hands-on cardboard geometric models, in classroom, in order to facilitate the understanding of fullerene structures. This approach to the study of such molecules represents a unique opportun
Quím. Nova. Publicado em: 2017-09
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6. Stress State at the Vertex of a Composite Wedge, One Side of Which Slides Without Friction Along a Rigid Surface
Abstract For studying the stress-strain state at singular points and their neighborhoods new concept is proposed. A singular point is identified with an elementary volume that has a characteristic size of the real body representative volume. This makes it possible to set and study the restrictions at that point. It is shown that problems with singular points
Lat. Am. j. solids struct.. Publicado em: 2017
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7. A SURVEY ON HEURISTICS FOR THE TWO-DIMENSIONAL RECTANGULAR STRIP PACKING PROBLEM
ABSTRACT Two-dimensional rectangular strip packing problems belong to the broader class of Cutting and Packing (C&P) problems, in which small items are required to be cut from or packed on a larger object, so that the waste (unused regions of the large object) is minimized. C&P problems differ from other combinatorial optimization problems by the intrinsic g
Pesqui. Oper.. Publicado em: 2016-08
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8. Nonlinear Characteristic of Spherical Joints with Clearance
ABSTRACT: Joints in deployable structures can degrade the stiffness and the stability of spacecraft. In this study, the nonlinear stiffness of spherical joints is investigated. The traditional contact model of spherical joints based on non-conforming contact assumption is presented. A new contact model for spherical joints based on the Winkler model and geom
J. Aerosp. Technol. Manag.. Publicado em: 2015-06
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9. A GRASP ALGORITHM FOR THE CONTAINER LOADING PROBLEM WITH MULTI-DROP CONSTRAINTS
This paper studies a variant of the container loading problem in which to the classical geometric constraints of packing problems we add other conditions appearing in practical problems, the multi-drop constraints. When adding multi-drop constraints, we demand that the relevant boxes must be available, without rearranging others, when each drop-off point is
Pesqui. Oper.. Publicado em: 2015-04
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10. An efficient formulation for linear and geometric non-linear membrane elements
Utilizing the straingradient notation process and the free formulation, an efficient way of constructing membrane elements will be proposed. This strategy can be utilized for linear and geometric non-linear problems. In the suggested formulation, the optimization constraints of insensitivity to distortion, rotational invariance and not having parasitic shear
Lat. Am. j. solids struct.. Publicado em: 2014-11
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11. Nonlinear Characteristics of Revolute Joints with Clearance
ABSTRACT: The nonlinear contact characteristic of revolute joint with clearance can degrade the performance of deployable structure. In this article, tensile and compressive tests are adopted to investigate the accuracies of the simplest conformal model and nonconformal model for contact, which are used to calculate the revolute joint deformation. In order t
J. Aerosp. Technol. Manag.. Publicado em: 2013-09
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12. Adaptive image denoising using scale and space consistency
This paper proposes a new method for image denoising with edge preservation, based on image multiresolution decomposition by a redundant wavelet transform. In our approach, edges are implicitly located and preserved in the wavelet domain, whilst image noise is filtered out. At each resolution level, the image edges are estimated by gradient magnitudes (obtai
Publicado em: 2011