Influência do comportamento semi-rígido de placas de base e de ligações viga-coluna na resposta dinâmica de pórticos de aço.

• Autor(a) principal: Lopes, Fernanda da Rocha de Carvalho
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/11559
• topic: Beam-to-column joints; Semi-rigid joints; Symmetrical and non-symmetrical joints; Column base plates; Nonlinear analysis; Forced vibration; Dynamic analysis; Finite elements method; Computational model; European codes; Ligações viga-coluna; Ligações semi-rígidas; Ligações simétricas e assimétricas; Placas de base; Análise não-linear; Vibração forçada; Análise dinâmica; Método dos elementos finitos; Modelo computacional; Normas européias; CNPQ::ENGENHARIAS::ENGENHARIA CIVIL

Traditionally, the steel portal frame design assumes that beam-to-column connections are rigid or pinned. Despite these facts, it is largely recognized that the great majority of joints does not exhibit such idealized behaviour. These connections are called semi-rigid, and their design should be performed according to their actual structural behaviour. Extensive research has been performed over the past twenty-five years to estimate the actual behaviour of such joints. One of the main objectives of this work is to propose an analysis methodology to properly represent the influence of the semi-rigid behaviour of base plates and beam-to-column joints on the dynamical response of steel structures (linear and non-linear). Another important investigated issue concerned the assessment of the steel frames dynamical behaviour (linear and non-linear) due to the presence of symmetrical and non-symmetrical beam-to-column semi-rigid joints and, especially, the column base plates. The structural analysis was made with the aid of the ANSYS [27] finite element program. The finite element model included geometric non-linearity, column base plates and beam-to-column non-linear behaviour and considered the influence of non-linear and hysteretic moment versus rotation curve of the joints. The results indicated that the resonance physical phenomenon was not reached in the nonlinear semi-rigid frames dynamic response. The resonance did not occurred in these systems due to the hysteretic damping induced by the energy dissipation of the non-linear hysteretic loops at the non-linear joints.