Infill masonry: simple analytical methods for seismic design

The latest earthquake codes in Europe require the safety assessment of no-structural elements (parapets, masonry wall’s veneer, infill walls, etc.), as their collapse entails risks for people or for the main structure stability. This work made possible th e development of a design method, supported by previous experimental researches by applying cyclic out-of-plane loads to damaged masonry infill in RC frames. Panels tested reproduce Portuguese traditional RC structure construction system and two reinforced solutions were created as innovative solutions. The experimental campaign was carried out in order to determine: masonry properties; out-of-plane panel behaviour with previous in-plane damage; building behaviour subjected to dynamic tests performed in shaking table. Using finite element method to reproduce experimental tests and to broaden the range of samples it was possible to figure out equations according to parametric analysis which was able to reproduce in-plane and out-plane behaviour leading to an estimated load bearing capacity of each model and to determine frame strength and its stiffness. Those equations permit to design or verify the masonry infill panels in RC frames subjected to seismic loads

Behavior of masonry infill panels in RC frames subjected to in plane and out of plane loads

The building envelope in Europe is usually made of masonry walls, with enclosure and infill functions. Masonry walls have a major economical importance and contribute significantly to the building performance. Even if infill walls have no load-bearing function, they contribute significantly to the seismic behavior of buildings. Therefore, their adequate structural performance is needed, avoiding the occurrence of severe in-plane damage, with very large economical losses, and the out-of-plane expulsion, which additionally represents a large risk for human life. Recent earthquake codes in Europe require the safety assessment of non-structural elements (parapets, veneer masonry walls, infill walls, etc.), when their collapse entails risks for people or for the main structure. The Eurocode standards, entering the mandatory stage now, incorporate new requirements to be fulfilled by buildings or their parts. Such is the case of masonry infilled RC frames whose panels, according to Eurocode 8, are explicitly required to withstand the out-of-plane movement induced by earthquakes. Appropriate measures should be taken to avoid brittle failure and premature disintegration of the infill walls, as well as the partial or total out-of-plane collapse of slender masonry panels. This paper presents the experimental work and results achieved by applying cyclic out-ofplane loads to damaged masonry infilled RC frames. The masonry panels were previously damaged by applying an in-plane cyclic load after which the cyclic out-of- plane loads were applied. The frames and panels tested follow the traditional Portuguese RC structure construction system to which different types of reinforcement have been introduced in the panels

Modelling of friction stir welding and its influence on the structural behaviour of aluminium stiffened panels

This work deals with the modelling and numerical simulation of aluminium stiffened panels, assembled by means of friction stir welding (FSW) operations, and subjected to compressive loads that can catastrophically induce buckling (global or local) unstable modes and, subsequently, overall failure. Due to their geometrical complexity, added to localized thermo-mechanical effects that typically come from joining by welding, approximation methods such as the Finite Element Method are typically used in such nonlinear analyses, having proved to be useful to designers focused on the prediction of the behaviour (before and post buckling) of such structures. Being grounded on previous contributions from the authors, the present paper aims to bring a number of innovative aspects to the current state of the art by considering in the developed models the simultaneous influence of residual stress fields, material softening effects and geometrical imperfections. Doing so, it is possible to infer about the singular and combined influence of these effects in the overall structural performance of stiffened panels, building up a useful and comprehensive methodology for design stages

Numerical simulation of the buckling behaviour of stiffened panels: Benchmarks for assessment of distinct modelling strategies

This work deals with the effective modelling and simulation of the behavior of stiffened panels, when subjected to compressive (buckling) loads. Within the Finite Element Method, two numerical strategies are compared, namely the Riks method and the displacement incremental control method, including damping effects. The capabilities and limitations of both approaches are explored for two distinct benchmarks: a panel with a blade stiffener, and a panel with a T shaped stiffener. In both cases, material (plasticity) and geometrical (large displacements) nonlinearities are considered, together with a modelling strategy based on shell elements. Following previous works of the authors, each panel accounts for initial geometric imperfections coming from friction stir welding joining operations. The paper shows a number of considerations that must be undertaken when choosing between one of the two modelling strategies. Both benchmarks involve a number of challenges from the point of view of modelling unstable structural behaviors, and therefore the proposed benchmarks can represent a valid set of case studies in the understanding of the capabilities of current numerical simulation codes

The thread unraveled: the great themes of traditional popular music in Brazil

Nos cantos, danças e folguedos populares brasileiros, podemos encontrar um feixe de motivos entrelaçados, padrões multicores de um tecido de que conviria procurar e acompanhar cada um dos fios aí urdidos e tramados, agrupando-os segundo sua textura ou coloração. Essas diferentes linhas temáticas, os fios da trama das expressões artísticas e religiosas do povo brasileiro são o assunto deste artigo, que procura analisar formas culturais caracterizadas pela hibridação, as quais transitam muitas vezes na ambiguidade entre resistência e aceitação de um padrão cultural dominante. O dinamismo dos arranjos de um certo número de motivos condutores recorrentes no âmbito da cultura de tradição oral brasileira nos leva a especular sobre os processos de formação de suas práticas artísticas, bem como sobre sua circulação num país de dimensões continentais.In the Brazilian popular chants, dances and festivities one can detect different motifs and patterns of a tissue. It is interesting to investigate and follow each of these threads that constitute this weft, grouping them according to their texture or coloring. These different thematic lines, threads of the weft of artistic and religious expressions of the Brazilian people are the theme of this article, which intends to analyze cultural forms characterized by hybridization which often resides in the ambiguity between resistance and acceptance of a dominant cultural pattern. The dynamism of these arrangements makes us speculate about the formation or constitution of these artistic practices, as well as their circulation, trying to investigate about the processes that were responsible for the broadcasting of these characteristics and similarities in such an enormous country

The thread unraveled: the great themes of traditional popular music in Brazil

Nos cantos, danças e folguedos populares brasileiros, podemos encontrar um feixe de motivos entrelaçados, padrões multicores de um tecido de que conviria procurar e acompanhar cada um dos fios aí urdidos e tramados, agrupando-os segundo sua textura ou coloração. Essas diferentes linhas temáticas, os fios da trama das expressões artísticas e religiosas do povo brasileiro são o assunto deste artigo, que procura analisar formas culturais caracterizadas pela hibridação, as quais transitam muitas vezes na ambiguidade entre resistência e aceitação de um padrão cultural dominante. O dinamismo dos arranjos de um certo número de motivos condutores recorrentes no âmbito da cultura de tradição oral brasileira nos leva a especular sobre os processos de formação de suas práticas artísticas, bem como sobre sua circulação num país de dimensões continentais.In the Brazilian popular chants, dances and festivities one can detect different motifs and patterns of a tissue. It is interesting to investigate and follow each of these threads that constitute this weft, grouping them according to their texture or coloring. These different thematic lines, threads of the weft of artistic and religious expressions of the Brazilian people are the theme of this article, which intends to analyze cultural forms characterized by hybridization which often resides in the ambiguity between resistance and acceptance of a dominant cultural pattern. The dynamism of these arrangements makes us speculate about the formation or constitution of these artistic practices, as well as their circulation, trying to investigate about the processes that were responsible for the broadcasting of these characteristics and similarities in such an enormous country

Prediction of Friction Stir Welding effects on AA2024-T3 plates and stiffened panels using a shell-based finite element model

Manufacturing-induced effects significantly affect in-service behaviour of welded structures, such as integrally stiffened panels for aeronautic applications. Being a complex phenomenon with several variables involved, the assessment of the effects coming from welding usually relies on numerical simulations. Here, a novel shell-based finite element model is proposed to accurately simulate the transient thermal fields and stress-strain distributions resulting from friction stir welding (FSW) processes. The capability of the model to predict (i) residual stresses, (ii) material softening and (iii) geometric distortion of the welded parts is assessed by the modelling and simulation of FSW applied on aluminium integrally stiffened panels

Micro-simulation of the impact of different speeds on safety road travel and urban travel time: case study in the city of Guimarães

In recent days, the use of micro-simulation as an additional tool for the study of the network makes this management faster and more efficient, avoiding in situ studies. However, although it is a useful tool, it is necessary that the model under study is the best represented possible in order to obtain results that best fit the reality of the road, and a poor calibration of the model can provide results that do not fit the good management of the road under study. In this sense, using micro-simulation, more precisely to the VISSIM PTV software, a road network at the microscopic level will be evaluated as well as the parameters that most influence the route of the users within that network. The parameters will be modified according to the modeler so as to obtain a model as close to reality as possible. The most appropriate criteria for the calibration and validation of the model will also be chosen. The road safety of the network will also be analyzed using the SSAM software. Here the network's points of conflict will be analyzed, characterizing them as to the type and its severity. Subsequently, a sensitivity analysis will be introduced, where some parameters will be modified individually or together, in order to assess their influence on the network, thus assessing the importance of each in the vehicles.(undefined

Biodegradation of textile azo dyes by a facultative Staphylococcus arlettae strain VN-11 using a sequential microaerophilic/aerobic process

A facultative Staphylococcus arlettae bacterium, isolated from an activated sludge process in a textile industry, was able to successfully decolourize four different azo dyes under microaerophilic conditions (decolourization percentage >97%). Further aeration of the decolourized effluent was performed to promote oxidation of the degradation products. The degradation products were characterized by FT-IR and UV–vis techniques and their toxicity with respect to Daphnia magna was measured. The amine concentrations as well as the total organic carbon (TOC) levels were monitored during the biodegradation process. The presence of aromatic amine in the microaerophilic stage and its absence in the aerobic stage indicated the presence of azoreductase activity and an oxidative biodegradation process, respectively. TOC reduction was ∼15% in the microaerophilic stage and ∼70% in the aerobic stage. The results provided evidence that, using a single Staphylococcus arlettae strain in the same bioreactor, the sequential microaerophilic/aerobic stages were able to form aromatic amines by reductive break-down of the azo bond and to oxidize them into non-toxic metabolites.The authors would like to thank the Portuguese Foundation of Science and Technology (FCT) for providing the grant to Andrea Zille (SFRH/BPD/24238/2005), and the Brazilian Foundation for the Coordination of the Improvement of University Graduates of the Ministry of Education (CAPES) and the National Research Counsel (CNPq) for providing the grants to Elisangela Franciscon

A reabilitação da rede rodoviária no século XXI : a contribuição da inovação para uma visão global da reabilitação rodoviária

Este artigo aborda a temática da reabilitação da rede rodoviária no contexto dos seus desafios para o futuro próximo. Inicialmente é feita uma abordagem da prática corrente dos processos seguidos na reabilitação e do seu impacto nos custos do ciclo de vida dos pavimentos. A seguir apresenta-se uma visão global da contribuição da reabilitação para a qualidade de vida. Por fim aborda-se o papel da inovação na engenharia rodoviária ao serviço da sociedade, compreendendo a inovação ao nível da qualidade de circulação e a construção e conservação sustentável dos pavimentos rodoviários