Št. zadetkov: 57
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Oznake:
dinamika konstrukcij;nelinearni nosilci;kinematična kompatibilnost;ohranjanje energije;rotacijski kvaternioni;implicitna časovna integracija;structural dynamics;non-linear beams;kinematic compatibility;energy conservation;rotational quaternions;implicit time integration;
In this paper, we present an original energypreserving numerical formulation for velocity-based geometrically exact three-dimensional beams. We employ the algebra of quaternions as a suitable tool to express the governing equations and relate rotations with their derivatives,while the finite-element ...
Leto:
2019
Vir:
Fakulteta za gradbeništvo in geodezijo (UL FGG)
Doktorska disertacija
Oznake:
Built Environment;civil engineering;doctoral thesis;geometrically exact beam;three-dimensional rotations;material softening;strain localization;arc-length method;embedded discontinuity;critical points;
Modeliranje nestabilnosti v konstrukcijah, ki so podvržene zahtevnejšim deformacijam, se običajno odraža v občutljivem obnašanju numeričnih metod reševanja in tako predstavlja pomemben izziv v numeričnem modeliranju. V disertaciji predstavljamo numerično formulacijo za analizo postkritičnega obnašan ...
Leto:
2024
Vir:
Fakulteta za gradbeništvo in geodezijo (UL FGG)
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Oznake:
valčki;skalirane funkcije;interpolacijske funkcije;linearna teorija nosilcev;diskretizacija;wavelets;scaling functions;shape functions;linear beam theory;discretization;
The paper presents the wavelet-based discretization of the linearized finite-strain beam theory which assumes small displacements, rotations and strains but is capable of considering an arbitrary initial geometry and material behaviour. In the numerical solution algorithm, we base our derivations on ...
Leto:
2009
Vir:
Fakulteta za gradbeništvo in geodezijo (UL FGG)
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Oznake:
kvaternioni;prostorski nosilci;prostorske rotacije;interpolacija rotacij;quaternions;three-dimensional beam;three-dimensional rotation;interpolation of rotations;
This paper presents the equations for the implementation of rotational quaternions in the geometrically exact three-dimensional beam theory. A new finite-element formulation is proposed in which the rotational quaternions are used for parametrization of rotations along the length of the beam. The fo ...
Leto:
2009
Vir:
Fakulteta za gradbeništvo in geodezijo (UL FGG)
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Oznake:
nelinearna teorija nosilcev;dinamična analiza;metoda končnih elementov;prostorska rotacije;kvaternioni;metoda Runge-Kutta;non-linear beam theory;dynamics analysis;finite element method;three-dimensional rotations;quaternion;Runge-Kutta methods;
The rotational quaternions are the unique four dimensional representation of rotations in three dimensional Euclidean space. In the present paper on the dynamics of non-linear spatial beams, they are used as the basic rotational parameters in formulating the finite-element approach of geometrically ...
Leto:
2012
Vir:
Fakulteta za gradbeništvo in geodezijo (UL FGG)
Diplomsko delo
Oznake:
krivulja;ploskev;minimalna ploskev;Dirichletov integral;Plateaujev problem;variacijski račun;prostori Soboljeva;
V diplomskem delu opišem in matematično formuliram Plateaujev problem za ploskve. Definiram pojem minimalne ploskve ter dokažem eksistenco rešitve Plateaujevega problema.
Leto:
1997
Vir:
Repozitorij Univerze v Ljubljani (RUL)
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Oznake:
gradbeništvo;nelinearne teorije;gradbena dinamika;numerične analize;končni elementi;gradiva;non-linear beam theory;non-linear material;reiforced concrete;stress field integration;Newton's iteration;rate of convergence;
The way the non-linear constitutive equations in the spatial beam formulations are solved, influences the rate of convergence and the computational cost. Three different approaches are studied: (i) the direct global approach, where the constitutive equations are taken to be the iterative part of the ...
Leto:
2008
Vir:
Fakulteta za gradbeništvo in geodezijo (UL FGG)
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Oznake:
linearna teorija nosilcev;ukrivljeni nosilci;zviti nosilci;konsistentna linearizacija;deformacijske količine;prostorski nosilci;prostorske rotacije;linear beam theory;naturally curved beam;twisted beam;consistent linearization;strain measure;three-dimensional beam;three-dimensional rotation;
This paper presents the equations of the linearized geometrically exact three-dimensional beam theory of naturally curved and twisted beams. A new finite-element formulation for the linearized theory is proposed in which the strain vectors are the only unknown functions. The linear form of the consi ...
Leto:
2006
Vir:
Fakulteta za gradbeništvo in geodezijo (UL FGG)
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Oznake:
armirani beton;prerezi;dvoosni upogib;analitična integracija;analytical integration;biaxial bending;reinforced concrete section;
This paper presents a novel stress field and tangent material moduli integration procedure over a cross-section of a biaxially loaded concrete beam. The procedure assumes a sufficiently simple analytical form of the constitutive law of concrete, the polygonal shape of the boundary of the simply- or ...
Leto:
2005
Vir:
Fakulteta za gradbeništvo in geodezijo (UL FGG)
Izvirni znanstveni članek
Oznake:
nelinearna teorija nosilcev;metoda končnih elementov;prostorske rotacije;non-linear beam theory;finite element method;three-dimensional rotation;
This paper introduces a new finite element formulation of the `geometrically exact finite-strain beam theory'. The formulation employs the generalized virtual work principle. In the resulting governing equations of the beam, the strain vectors are the only unknown functions. The consistency conditio ...
Leto:
2004
Vir:
Fakulteta za gradbeništvo in geodezijo (UL FGG)