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Percorrer CDRsp - Comunicações em conferências internacionais por Domínios Científicos e Tecnológicos (FOS) "Ciências Naturais::Outras Ciências Naturais"
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- Analysis of the influence of cladding panels in the seismic behaviour of a prc industrial buildingPublication . Ostetto, Liana; Sousa, Romain; Rodrigues, Hugo; Fernandes, PauloRecent reports on the latest earthquakes in Italy and Turkey have highlighted some critical problems in the connections of cladding panels on industrial precast reinforced concrete (PRC) structures. The panel connections did not perform as expected, causing non-structural damages and, in most cases, leading to the panels overturning. The damage and collapse of these elements may result in significant losses of human lives and large socio-economic impacts due to business interruption. Despite being demonstrated that cladding panels can have a significant contribution on seismic response, these elements are often considered as non-structural, ignoring the interaction with the RC frame, and considering that they do not influence the seismic behaviour. Making use of a simplified macro element, this study assesses the seismic capacity of commonly employed claddings-to-structure connections, as well as the interaction of the cladding panels with the PRC industrial buildings. The analyses were carried out considering a PRC building representative of the Portuguese industrial park, studied with and without cladding panels. The seismic behaviour of the structure are assess considering both non-linear static and dynamic procedures.
- Assessment of existing rc precast industrial buildings according with eurocode 8 - part 3Publication . Batalha, Nádia; Rodrigues, Hugo; Sousa, Romain; Varum, Humberto; Fernandes, PauloPrecast reinforced concrete (PRC) buildings are common in the Portuguese industrial park, as well as throughout Europe. In past earthquakes, namely in Italy and Turkey, this typology of buildings showed a poor performance, namely at structural level. One of the major concerns at structural level regards the connection between the beams and columns. In recent surveys at the Portuguese industrial buildings, it was observed that the buildings built before 1980 present, most of the times, only friction connections between beam and columns. This type of connection is pointed as one of the weakest structural system in this typology of structures and consequently led to serious local and global damage when subjected to seismic loads. Regarding this issue, it was considered appropriate and necessary the study of existing Portuguese buildings with this type of beam-to-column connection and compare it with the use of mechanical connections (dowels), which is a more common solution in the recent buildings. The seismic behaviour of two PRC buildings built with these two solutions was analysed considering nonlinear static and dynamic analyses addressing both global and local (connections) response parameters. When analysed in view of the seismic regulation for existing buildings (Eurocode 8 –Part 3), the results obtained show that, overall, this typology of buildings present an acceptable structural performance. Nonetheless, unsatisfactory performance was observed at the beam-to-column connection in one of the buildings built without steel dowels. The results presented in this study highlight the need to consider adequate models to simulate these connections in order to accurately represent the seismic behaviour on the structure and identify possible limitations in the use of nonlinear static procedures to assess the seismic performance of this typology of buildings. In general, the buildings in study, located in a region of moderate seismicity, exhibited a satisfactory behaviour. However particular attention should be paid to beam-to-column connections, especially in the case of friction connections. In this regard it is important to accurately represent in the model the mechanisms involved in the connections, particularly in buildings located in moderate to high seismic zones.
- Cyclic plastic behaviour of 7075 aluminium alloyPublication . Nogueira, F.; Cunha, J.; Mateus, A.; Malça, C.; Costa, J. D.; Branco, R.This paper aims at studying the cyclic plastic behaviour of the 7075-T651 aluminium alloy under fully-reversed strain-controlled conditions. Tests are conducted under strain-control mode, at room temperature, in a conventional servo-hydraulic machine, from smooth samples, using the single step method, with strain amplitudes (∆ε/2) in the range ±0.5 to ±2.75%. This material has exhibited a mixed behaviour, i.e. cyclic strain-hardens at higher strain amplitudes (∆ε/2/>1.1%) and cyclic strain-softens at lower strain amplitudes (∆ε/2<1.1%). A linear relationship between the degree of cyclic strain-hardening and the strain amplitude has been established for higher strain amplitudes. Fatigue-ductility and fatigue-strength properties agree with those found in the open literature for the same loading conditions.