Encontrados 22 documentos, a visualizar página 1 de 3
Numerical modelling of the punching behaviour of steel fibre reinforced self-co...
Barros, Joaquim A. O.; Teixeira, Marcos D. E.; Cunha, Vítor M. C. F.; Moraes-Neto, B. N.; Gouveia, A. VenturaPunching shear failure on flat reinforced concrete slabs of residential and commercial buildings is generally avoided by using transversal reinforcement and/or chapiters. The first option requires intense labour, mainly when densely flexural reinforcement exists in the potential punching failure region, with detrimental consequences in terms of costs of this construction solution. The second option has also ext...
Model to simulate the behaviour of RC beams shear strengthened with ETS bars
Barros, Joaquim A. O.; Breveglieri, Matteo; Gouveia, A. Ventura; Dalfré, Gláucia; Aprile, AlessandraTo predict correctly the deformational and the cracking behavior of reinforced concrete elements failing in shear using a smeared crack approach, the strategy adopted to simulate the crack shear stress transfer is crucial. For this purpose, several strategies for modeling the fracture mode II were implemented in a smeared crack model already existing in the FEM-based computer program, FEMIX. Special development...
A FEM-based model to predict the behaviour of RC beams shear strengthened accor...
Barros, Joaquim A. O.; Baghi, Hadi; Dias, Salvador J. E.; Gouveia, A. VenturaExperimental research has demonstrated the excellent performance of the near surface mounted (NSM) technique with carbon fibre reinforced polymer (CFRP) laminates for the shear strengthening of reinforced concrete (RC) beams. This paper presents a finite element analysis to evaluate the behaviour of RC beams shear strengthened with NSM CFRP laminates. To predict correctly the deformational and the cracking beha...
Aplicação de microbetão para o reforço de elementos estruturais em betão armado...
Cunha, Frederico; Lourenço, Lúcio; Gonçalves, Delfina; Barros, Joaquim A. O.; Gouveia, A. VenturaNo presente trabalho avalia-se a eficácia de uma técnica de reforço para elementos estruturais em betão armado afetados pela exposição a temperaturas elevadas e/ou fogo. Para tal, desenvolveu-se um programa experimental que incluiu a moldagem de catorze provetes prismáticos (150 x 150 x 600 mm 3 ) em betão de classe resistente corrente em estruturas de betão armado existentes no edificado português (C20/...
Crack constitutive model for the prediction of punching failure modes of fiber ...
Barros, Joaquim A. O.; Gouveia, A. Ventura; Azevedo, Álvaro F. M.The capability of a multi-directional fixed smeared crack constitutive model to simulate the flexural/punching failure modes of fiber reinforced concrete (FRC) laminar structures is discussed. The constitutive model is implemented in a computer program based on the finite element method, where the FRC laminar structures were simulated according to the Reissner-Mindlin shell theory. The shell is discretized into...
CFRP flexural and shear strengthening technique for RC beams : experimental and...
Barros, Joaquim A. O.; Costa, Inês; Gouveia, A. VenturaNear surface mounted (NSM) technique has proved to be a very effective technique for the flexural strengthening of RC beams. Due to the relatively small thickness of the concrete cover that several beams present, cutting the bottom arm of steel stirrups for the installation of NSM laminates might be a possible strategy, whose implications on the beam’s load carrying capacity need to be assessed. When steel stir...
Constitutive models for the material nonlinear analysis of concrete structures ...
Gouveia, A. VenturaTese de doutoramento Estruturas /Engenharia Civil ; In recent years concrete technology has been improved significantly due, mainly, to the development of self-compacting concrete, ultra-fluid cement based materials, high performance fiber reinforced concrete and engineered cement composites. These developments have their main applicability in the pre-casting industry, where the earliest demoulding of the pre-...
Multi-fixed smeared 3d crack model to simulate the behavior of fiber reinforced...
Gouveia, A. Ventura; Barros, Joaquim A. O.; Azevedo, Álvaro F. M.; Sena-Cruz, JoséWhen a concrete structure is subjected to a multi-stress state, different crack modes can be developed. To simulate with enough accuracy these fracture modes, a three dimensional model must be used. In the present work, a multi fixed smeared 3D crack model is proposed to predict the normal and shear failure modes of concrete structures. Softening stress strain diagrams are proposed to model, after crack initiat...
Numerical simulation of thin steel fiber self-compacting concrete structures
Barros, Joaquim A. O.; Pereira, E. N. B.; Gouveia, A. Ventura; Azevedo, Álvaro F. M.Steel Fiber Reinforced Self Compacting Concrete (SFRSCC) was developed and applied on the manufacture of structural façade panels composed of a grid ribbed system covered by a layer of 30 mm thickness. Panel prototypes of this structural system were tested using loading configurations that promote the flexural and the punching failure modes in order to assess the benefits of fiber reinforcement to the flexural ...
Crack constitutive model to simulate the behavior of fiber reinforced concrete ...
Gouveia, A. Ventura; Barros, Joaquim A. O.; Azevedo, Álvaro F. M.; Sena-Cruz, JoséFor some structural applications, mainly with redundant supports, adding fibers to concrete can be an economic strategy, especially when shear brittle failure mode has a high risk of occurrence. In the present work, a crack constitutive model is proposed to simulate localized failure modes due to punching. The performance of the developed constitutive model was appraised by simulating the behavior observed in p...
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