21 documents found, page 1 of 3
An Image-Based Framework for Measuring the Prestress Level in CFRP Laminates: E...
Valença, Jónatas; Ferreira, Cláudia; Araújo, André G.; Júlio, EduardoImage-based methods have been applied to support structural monitoring, product and material testing, and quality control. Lately, deep learning for compute vision is the trend, requiring large and labelled datasets for training and validation, which is often difficult to obtain. The use of synthetic datasets is often applying for data augmentation in different fields. An architecture based on computer vision w...
Modelação Numérica do Comportamento de um Sistema Inovador de Proteção de Edifí...
Gomes, Gabriel; Pires,Luís; Júlio, EduardoA vida humana, ocasionalmente é ameaçada. O estudo de um sistema de proteção para infraestruturas contra explosões pode ajudar a mitigar algumas dessas ameaças. No âmbito da tese de doutoramento do TCor. Gabriel Gomes, desenvolveu-se um sistema de proteção inovador. Foi testado com sucesso e as suas capacidades foram comprovadas. O presente trabalho pretende contribuir através do desenvolvimento de uma análise ...
Flexural behavior of slender long‐span precast prestressed high‐strength concre...
Fernandes, Paulo; Cavaco, Eduardo; Maranha, Paulo; Júlio, EduardoThe flexural behavior of slender (1/40) long-span precast high-strength concrete girders was experimentally investigated as a competing solution to steel alternatives for highway overpasses. Half-scale specimens were produced using an economical and high-strength (120 MPa) concrete mixture, non-fiber reinforced, designed only with conventional raw materials, currently available at Portuguese precast companies. ...
Analytical hybrid effect prediction and evolution of the tensile response of un...
Ribeiro, Filipe; Sena-Cruz, José; Branco, Fernando G.; Júlio, Eduardo; Castro, FernandoThe performance of a progressive damage model in quantitative hybrid effect prediction of a comprehensive set of different 16 unidirectional interlayer (layer-by-layer) hybrid composites was assessed. Composites, produced by the hand lay-up method, made out of 4 different commercially available dry unidirectional fabric materials, namely high-modulus carbon, standard carbon, E-glass and basalt were tested. Tens...
Admixture tuning for high‐performance concrete for the production of novel prec...
Fernandes, Paulo; Pala, Helena; Cavaco, Eduardo; Tiago, Paulo; Júlio, EduardoThe improvements observed in concrete technology in the last decades, namely the production of Portland cement CEM I 52.5 R, the development of third generation super-plasticizers, and the commercialization of additions with high pozzolanic properties, turned possible the development of new concrete products using high performance concrete (HPC). Nevertheless, their implementation in the production process of t...
3D finite element model for hybrid FRP-confined concrete in compression using m...
Ribeiro, Filipe; Sena-Cruz, José; Branco, Fernando G.; Júlio, EduardoThe main goal of the work herein presented is to propose an accurate three-dimensional finite element model to predict the compressive behaviour of hybrid FRP-confined concrete. This was achieved through the modification of the concrete damaged plasticity model (CDPM) available in ABAQUS software, since the original CDPM has shortcomings that make it unusable to predict the compressive behaviour of confined con...
Hybrid FRP jacketing for enhanced confinement of circular concrete columns in c...
Ribeiro, Filipe Jorge Teixeira; Sena-Cruz, José; Branco, Fernando; Júlio, EduardoThe main goal of the study herein described was to evaluate the performance of an innovative confining unidirectional hybrid FRP solution for circular concrete columns, exploiting the hybrid effect and pseudo-ductility of FRP jackets made of different fibres. First, an experimental study on the compressive stress-strain curves of small-scale plain circular concrete columns confined with hybrid FRP was conducted...
Hybrid effect and pseudo-ductile behaviour of unidirectional interlayer hybrid ...
Ribeiro, Filipe; Sena-Cruz, José; Branco, Fernando G.; Júlio, EduardoAn experimental study on the tensile stress–strain curves of interlayer (layer-by-layer) unidirectional hybrid FRP composites was conducted aiming at evaluating the corresponding hybrid effect and pseudo-ductility of this innovative solution. Different combinations of the following dry unidirectional fabric materials, also varying the number of layers, were adopted in tests: high-modulus carbon, standard carbon...
Axial compressive behaviour of hybrid FRP confined concrete
Ribeiro, Filipe; Sena-Cruz, José; Júlio, Eduardo; Branco, FernandoFibre Reinforced Polymers (FRP) composites can be effectively used as passive confinement system of concrete columns. Regarding to this option, however, two main drawbacks can be pointed out: (i) in several cases the ultimate lateral strain in the confinement is significantly lower than the tensile strain at failure of the composite, and (ii) the conventional composites experience brittle failure, in an explosi...
Comportamento à compressão de pilares circulares de betão confinados por sistem...
Ribeiro, Filipe; Sena-Cruz, José; Branco, Fernando; Júlio, EduardoNo presente trabalho apresenta-se um estudo analítico-experimental sobre o comportamento à compressão de provetes circulares em betão encamisados com um inovador sistema compósito de FRP híbrido. No referido sistema procurou-se explorar as vantagens da utilização combinada de uma única matriz epoxídica reforçada com várias mantas constituídas por fibras de reforço de diferentes materiais, nomeadamente carbono d...