1,721,200 research outputs found
DESIGN FOR ROBUSTNESS OF A PILOT BUILDING EQUIPPED WITH DISSIPATIVE FREE FROM DAMAGE STEEL CONNECTIONS
No full textRecent research initiative aimed at reducing the structural damage and its inherent economic consequences in steel and steel-concrete composite structures after severe earthquakes led to the development of FREE from DAMage (FREEDAM) beam-to-column connections. The practical applicability and the benefits of using these connections for structures in seismic areas are currently demonstrated within an ongoing RFCS pilot project to be built on the campus of the University of Salerno. Amongst the different structural requirements, Euro-codes nowadays require providing the structures with an appropriate robustness when subjected to identified or unidentified accidental events by ensuring that the undergone damages are not disproportionate to the initiating cause. This paper presents the design for robustness of the pilot building. The results indicate that the loss of a column at the base floor induces the development of significant catenary action in the beams bridging over the lost column. The structural performance under the column loss scenario is primarily governed by the behaviour of beam-to-column joints subsequently identified as critical zones. The full-range behaviour of the FREEDAM joints was investigated through complex numerical simulations which allowed validating a simplified component-based spring model that can be adopted for the regular design of structures adopting this joint typology
Experimental and numerical investigation of a reinforced concrete building designed for gravity loads only
No full textNew Resilience Index for Urban Water Distribution Networks
Full text linkThe increased frequency of natural disasters and man-made catastrophes has caused major disruptions to critical infrastructures (CI) such as water distribution networks (WDNs). Therefore, reducing the vulnerability of the systems through physical and organizational restoration plans are the main concern for system engineers and utility managers that are responsible for the design, operation, and protection of WDNs. In this paper, a resilience index (R) of a WDN has been proposed that is the product of three indices: (1)the number of users temporarily without water, (2)the water level in the tank, and (3)the water quality. The resilience index is expected to help planners and engineers evaluate the functionality of a WDN, which includes: (1)delivering a certain demand of water with an acceptable level of pressure and quality, and (2)the restoration process following an extreme event. A small town in the south of Italy has been selected as a case study to show the applicability of this index using different disruptive scenarios and restoration plans. The numerical results show the importance of the partition of the network into districts to reduce the lack of services. It is also necessary to consider the indices separately to find trends that cannot be captured by the global index. Advantages and disadvantages of the different restoration plans are discussed. The proposed indices can be implemented in a decision support tool used by governmental agencies that want to include the restoration process, and the environmental and social aspects in their design procedure
Valorisation of knowledge for European prequalified steel joints: The equalJoints plus project
No full textWithin the previous RFCS project EQUALJOINTS (RFSR-CT-2013-00021), seismic prequalification criteria of steel joints have been developed. The EQUALJOINTS-PLUS project aims at the valorisation, the dissemination and the extension of the developed prequalification criteria for practical applications to a wide audience (i.e. academic institutions, Engineers and architects, construction companies, steel producers). The main objectives of the project are the following: to collect and organize informative material concerning the prequalified joint typologies: informative documents will be prepared in 12 languages (English, Spanish, French, German, Italian, Dutch, Portuguese, Czech, Bulgarian, Romanian, Greek, and Slovenian), to develop pre-normative design recommendations of seismically qualified joints on the basis of results from Equaljoints project, to develop design guidelines in order to design steel structures accounting for the type of joints and their relevant nonlinear response, to develop a software and an app for mobile to predict the inelastic response of joints, to organize seminars and workshops in EU countries and the USA for disseminating the gained knowledge, to create a web site with free access to the users in order to promote the obtained results, to create a You-Tube channel to make available the videos of the experimental tests and simulations to show the evolution of damage pattern
THE USE OF STRUCTURAL TIMBER IN EUROPE: AN OVERVIEW ON RECENT DEVELOPMENTS
Full text linkThe prerogatives of sustainability, excellent strength-to-weight ratio and high prefabrication level, make the structural timber as a highly performant construction material widely used in Europe for new constructions or for retrofitting the existing ones. The recent development of structural timber was due to the introduction of engineered wood products that gave the possibility to realize buildings for residential and commercial destinations, also in seismic- prone areas. Moreover, in the light of the Next Generation EU Plan - released be the European Parliament as aid to the economy recovery following the covid-19 pandemic - which introduced the concept of green transition to reduce emissions of carbon dioxide into the atmosphere, timber surely occupies a prominent place among the building materials. This paper deals with an insight on the use of timber in Europe as sustainable, green, and highly seismic and energetic performant construction material. The aim is that of providing a comprehensive overview on the state-of-art and highlighting recent advancements and future trends both in research field and engineering practice in Europe. Particular emphasis is paid to (i) new timber-based products and/or subassemblies used for low, medium and high-rise seismic-resistant constructions; (ii) timber-based solution for combined seismic and energetic retrofit of existing masonry and reinforced concrete buildings; (iii) new prospective of short chains to improve life cycle of material and its impact on environment, (iv) codes and guidelines. The peculiarities of each topic treated are discussed in detail
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Machine learning-based identification of vulnerability factors for masonry buildings in aggregate: The historicalcentre of casentino hit by the 2009 l'aquila earthquake
No full textSeismic events in Italy and worldwide have highlighted the high vulnerability of unreinforced masonry (URM) structures in small historical centres. A key feature of these settlements is to be mostly composed of buildings in aggregate, i.e., interconnected by a more or less structurally effective connection. The seismic assessment of such buildings is quite debated in the literature and no shared tools procedures are currently available. The difficulty of standardization derives from the fact that structural units can be characterized by multiple features and configurations that determine a vast number of vulnerability factors, whose interdependency is not straightforward to be identified. The paper addresses this issue by combining evidence-based damage data with the potential offered by Machine Learning (ML) technique. Real data are used in combination with state-of-the-art ML algorithms carefully tuned via an advanced statistical procedure for two main purposes. The first one will be able to predict possible URM damages based on the vulnerability factor in both interpolation and extrapolation scenarios. The second purpose of the ML-based techniques will be to predict the most important vulnerability factors in making these predictions, namely to make the ML-based model explainable and informative about the underlying phenomena and not just predictive. The small historic centre of Casentino, hit by the 2009 L'Aquila earthquake, is adopted in the paper as the first test case study. A large amount of data was collected after the earthquake through in-situ surveys made by the Universities of Genova, Catania and Rome. Data include both geometric and structural factors, i.e., the input data supplied to the ML algorithm, as well as the actual seismic damage mechanisms, i.e., the output data expected to be predicted by the ML algorithm. As first application, ML techniques are applied only to data acquired on out-of-plane mechanisms.The study presented in the paper was developed within the research activities carried out in the frame of 2022-2024 ReLUIS Project – WP10 Masonry Structures (Coordinator - Prof. Guido Magenes). This project has been funded by the Italian Department of Civil Protection. Note that the opinions and conclusions presented by the authors do not necessarily reflect those of the funding entity.Ship Design, Production and Operation
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