1,720,959 research outputs found
SSI on the dynamic behavior of a historical masonry building: experimental vs. numerical results
No full textA reliable procedure to identify the dynamic behaviour of existing masonry buildings is described in the paper, referring to a representative case study: a historical masonry palace located in Benevento (Italy). Since the building has been equipped with a permanent dynamic monitoring system by the Department of Civil Protection, some of the recorded data, acquired in various operating conditions, have been analysed with basic instruments of the Operational Modal Analysis in order to identify the main eigenfrequencies and vibration modes of the structure. The obtained experimental results have been compared to the numerical outcomes provided by three detailed Finite Element (FE) models of the building. The influence of Soil-Structure Interaction (SSI) has been also introduced in the FE model by a sub-structure approach where concentrated springs were placed at the base of the building to simulate the effect of soil and foundation on the global dynamic behaviour of the structure. The obtained results evidence that subsoil cannot a priori be disregarded in identifying the dynamic response of the building
Dynamic monitoring of guardrails: approach to a low-cost system
No full textGuardrails are common basic roadside devices used to prevent vehicles from leaving the roadway. It is important to ensure their performance through adequate maintenance. A low-power, low-cost wireless sensor network and a simplified structural modeling can be used to remotely monitor the health of a guardrails system. In this paper, the concept of such a system and some early experimental tests are presented
Soil-structure interaction: the case study of a masonry tower
No full textIn recent years the development of more and more advanced design softwares, able to take into account complex aspects in structural modelling, allows the interaction between the structure and the foundation soil to be properly modelled. Soil-structure interaction is certainly a typical subject but, nevertheless, still new in its applicative aspects. Further studies are necessary for converting the research highlights in practical tools for routine structural analysis. Dynamic soil-structure interaction problems can be treated in different ways; the main distinction is between direct and the substructure approaches. In thiswork, the F.E. software DIANA(TNO, Delft) has been adopted to solve SSI problems. Soil has been modeled as a 3D elastic medium, discretized by eight-node solid brick elements. In the first stage of the modeling, it was necessary to evaluate the proper sizes of the soil volume to be included in the F.E. model and of the mesh elements. Validation of the developed F.E. model was carried out by comparing the impedances obtained from DIANA analyses to the values provided in literature for shallow foundations. In the final part, the paper illustrates an application of the above procedure on a real building, the Bell Tower of S. Maria del Carmine Church in Naples, representative of many other masonry towers present in Italy and vulnerable to seismic load
Soil-structure interaction on the dynamic response of bridge piers
No full textThe paper analyses the effect of Soil-Structure-Interaction (SSI) on the modal dynamic response of simply-supported span girder bridge with wall piers founded on caissons. A parametric analysis has been carried out in the hypothesis of linear elastic behaviour of all materials (soil and structure) to identify the influence of various design factors, such as the height of the pier, the caisson embedment below the ground level and the soil mechanical properties. The goal of the paper is to highlight SSI effects on the dynamic behaviour of bridges. This is a crucial aspect to be accounted for in order to support monitoring activities on bridges, aimed to structural identification or assessment of structure response under serviceability conditions, or also to have preliminary information for the seismic analysis of the bridge
Bond behavior of geopolymer concrete with steel and GFRP bars
No full textIn the last years geopolymer concrete (GPC) has shown great potential for use in structural elements. In this context, it has become fundamental to investigate on the bond behavior of this new concrete matrix with reinforcing bars. Data found in literature showed that GPC performs better than ordinary Portland cement (OPC) concrete in terms of bonding with deformed steel bars. In addition, few authors have focused in the study of the bond stress-slip behavior between GPC and glass fiber-reinforced polymer (GFRP) rebars. In this paper the bond -slip behavior of GPC with both steel and GFRP reinforcing bars will be investigated by means of pull-out test with centered bar setup also considering the effect of the bond length. The main results showed that little difference in bond-slip behavior occur between the two different steel bar diameters used. On the other hand, sand-coated GFRP bars showed lower bond capacity in respect to deformed steel bars. Finally, an increase in ultimate bond load has been observed when the bond length was increased
Influenza del sottosuolo sul campanile del Carmine a Napoli
No full textLa nota descrive l’identificazione dinamica del campanile del Carmine a Napoli, effettuata attraverso analisi
dinamiche su un modello tridimensionale del sistema terreno - fondazione - struttura, tarato sui risultati di
dettagliate indagini in situ. Sono stati riconosciuti fenomeni di risonanza tra la frequenza fondamentale del
terreno e la seconda frequenza di vibrazione della struttura che ne condizionano il comportamento dinamic
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
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