Loading...
Publication
Efeito do escorregamento dos varões no recentramento de estruturas de betão armado
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 1.23 MB | Adobe PDF |
Advisor(s)
Abstract(s)
À medida que o conhecimento da resposta das estruturas de betão
armado solicitadas por sismos foi sendo adquirido, a perceção da
importância do controlo dos deslocamentos máximos e residuais,
para reduzir danos e tornar a reparação economicamente viável, foi
aumentando.
A resposta no tempo de um pórtico de betão armado, acoplado a
vários tipos de dissipadores (elasto-plásticos, viscosos e baseados
em ligas com memória de forma – passivos e semiativos) foi
avaliada. O comportamento não linear da estrutura, incluindo o
escorregamento dos varões nos nós das vigas-colunas, foi modelado
com elementos finitos de fibras. Para comparação, realizaram-se
também análises com aderência perfeita.
As soluções histeréticas passivas não reduziram satisfatoriamente os
deslocamentos, enquanto os dissipadores semiativos resultaram em
deslocamentos máximos semelhantes aos dos dissipadores viscosos
lineares. A comparação das respostas com escorregamento e com
aderência perfeita permite observar diferenças significativas, tanto
nos deslocamentos máximos como nos deslocamentos residuais.
As the body of knowledge regarding the response of reinforced concrete structres subjected to seismic actions has grown, the awareness of the importance of controlling both peak and residual displacements, to reduce the structural damage and avoid excessively high repair costs, increased. Nonlinear dynamic analysis of a reinforced concrete frame, coupled with a variety of energy dissipation devices (steel hysteretic, viscous and shape memory alloy-based – passive and semi-active) was performed. The nonlinear behaviour of the materials was modelled, including the bond-slip of the rebars, using fiber-based finite elements. For comparison, perfect bond analyses were also performed. Hysteretic passive solutions did not satisfactorily reduced the displacements, while the peak displacements with semi-active devices are similar to those of the linear viscous dampers. The comparison of the responses with bond-slip and with perfect bond shows significant differences in both peak and residual displacements.
As the body of knowledge regarding the response of reinforced concrete structres subjected to seismic actions has grown, the awareness of the importance of controlling both peak and residual displacements, to reduce the structural damage and avoid excessively high repair costs, increased. Nonlinear dynamic analysis of a reinforced concrete frame, coupled with a variety of energy dissipation devices (steel hysteretic, viscous and shape memory alloy-based – passive and semi-active) was performed. The nonlinear behaviour of the materials was modelled, including the bond-slip of the rebars, using fiber-based finite elements. For comparison, perfect bond analyses were also performed. Hysteretic passive solutions did not satisfactorily reduced the displacements, while the peak displacements with semi-active devices are similar to those of the linear viscous dampers. The comparison of the responses with bond-slip and with perfect bond shows significant differences in both peak and residual displacements.
Description
Keywords
Betão armado Escorregamento Recentramento Deslocamentos residuais Reinforced concrete Bond-slip Re-centring Residual displacements . Faculdade de Artes e Humanidades
Citation
LOBO, P. [et al.] – Efeito do escorregamento dos varões no recentramento de estruturas de betão armado. Revista Portuguesa de Engenharia de Estruturas. Ed. LNEC. Série III. n.º 5. ISSN 2183-8488. (novembro 2017) 45-52.
Publisher
LNEC - Laboratório Nacional de Engenharia Civil