13 documents found, page 1 of 2
Transversally loaded stainless steel beams under fire: Local/global behaviour, ...
Martins, André Dias; Camotim, Dinar; Gonçalves, Rodrigo; Lopes, Nuno; Vila Real, PauloThis paper presents and discusses the results of a numerical investigation concerning the post-buckling behaviour, strength and design of stainless steel I-section beams prone to local or global (lateral-torsional) buckling under elevated temperatures. Non-linear shell finite element models are employed to assess the structural response and failure loads of I-beams (i) subjected to distinct loading conditions, ...
Formulação da Teoria Generalizada de Vigas para calcular cargas de bifurcação l...
Henriques, David; Gonçalves, Rodrigo; Camotim, DinarApresenta-se um elemento finito baseado na Teoria Generalizada de Vigas (ou GBT, Generalized Beam Theory) para calcular, com eficiência computacional e precisão, cargas de bifurcação laterais-distorcionais em vigas mistas aço-betão. A determinação das cargas de bifurcação é realizada em duas etapas: (i) uma análise de pré-encurvadura, que contabiliza os efeitos de shear lag e da fendilhação do betão, e (ii) uma...
Um método global para a verificação da segurança de colunas e vigas contínuas d...
Gonçalves, Rodrigo; Camotim, DinarApresenta-se um método de verificação da segurança que (i) se baseia em parâmetros que caracterizam o comportamento global da estrutura e (ii) é totalmente consistente com o método de aplicação das curvas de encurvadura do EC3. Mostra-se que a abordagem proposta, para além de evitar verificações desnecessárias, (i) fornece informações muito relevantes acerca da eficiência estrutural do sistema e (ii) possibilit...
Efficient GBT displacement-based finite elements for non-linear problems
Gonçalves, Rodrigo; Camotim, DinarThis paper addresses computational efficiency aspects of Generalized Beam Theory (GBT) displacement-based finite elements. It is shown that such efficiency can be significantly improved by using cross-section nodal DOFs (instead of deformation modes) since much smaller matrices need to be handled and the element stiffness matrix becomes significantly sparser. In addition, wall thickness variations, including ho...
Aplicação da Teoria Generalizada de Vigas ao estudo da interacção distorcional-...
Martins, André; Camotim, Dinar; Gonçalves, Rodrigo; Dinis, PedroO primeiro autor agradece o apoio financeiro da Fundação para a Ciência e a Tecnologia (FCT – Portugal), através da bolsa de doutoramento SFRH/BD/87746/2012.
On the mechanics of local-distortional interaction in thin-walled lipped channe...
Martins, André; Camotim, Dinar; Gonçalves, Rodrigo; Dinis, PedroThis paper investigates the elastic post-buckling behavior of simply supported thin-walled lipped channel beams undergoing local-distortional (L-D) interaction. The beams are uniformly bent about the major-axis and experience flange - triggered local buckling (most common situation in practice). Three beams are analyzed, each exhibiting a different type of L-D interaction, namely (i) “true L – D-interaction” (c...
GBT-based buckling analysis using the exact element method
Bebiano, Rui; Eisenberger, Moshe; Camotim, Dinar; Gonçalves, RodrigoGeneralised Beam Theory (GBT), intended to analyse the structural behaviour of prismatic thin-walled members and structural systems, expresses the member local and/or global deformed configuration as a combination of cross-section deformation modes multiplied by the corresponding longitudinal amplitude functions. The determination of the latter, usually the most computer-intensive step of the analysis, is almos...
Mechanics of Distortional-Global Interaction in Fixed-Ended Lipped Channel Columns
Martins, André; Camotim, Dinar; Gonçalves, Rodrigo; Dinis, PedroThis work reports the results of a numerical investigation concerning the elastic post-buckling behaviour offixed-endedthin-walledlipped channelcolumnsaffected bydistortional-global(D-G)interaction. The columns analysed (i) exhibit cross-section dimensions and lengths ensuring simultaneous distortional and global critical buckling loads, and (ii) contain critical-mode initial geometrical imperfections (linear c...
First-order Generalized Beam Theory for Curved Members with Circular Axis
Peres, Nuno; Gonçalves, Rodrigo; Camotim, DinarThis paper presents a first-order Generalized Beam Theory (GBT) formulation for thin-walled members with circular axis and undergoing complex global-distortional-local deformation. The fundamental equations are derived on the basis of the usual GBT kinematic assumptions (Kirchhoff, Vlasov and wall in-plane inextensibility), leading to a formulation able to retrieve accurate solutions with only a few cross-secti...
Recent Developments in the GBT-Based Numerical Modeling of Steel-Concrete Compo...
Gonçalves, Rodrigo; Henriques, David; Camotim, DinarThis paper presents the latest developments concerning the numerical modeling ofsteel-concrete composite beams using GBT-based (beam) finite elements. In particular, it is shown that GBT makes it possible to assess, accurately and with computational efficiency, the buckling (bifurcation) behavior of steel-concrete composite beams subjected to negative (hogging) bending. Two relevant buckling phenomena are consi...