1,720,959 research outputs found
Seismic response of single-storey steel buildings: role of design criteria.
Get PDFItalian and European codes allow constructions in seismic areas to be designed with either dissipative or elastic structural behaviour. In the first case, the concept of capacity design is the basis of structural dimensioning; both strength and ductility verifications are required. In the second case, structural elements are designed to remain in the elastic field under the assigned design seismic input; ductility verifications are not enforced. These two design approaches might lead to very different seismic performances depending on the role of the non-ductile elements and connections in the elastic design. In fact, the non-ductile elements and connections might represent a source of weakness and lead to premature failures. In the present work, critical issues related with the modelling of the post-elastic behaviour of a non-dissipative single-storey industrial steel structure are discussed and comparisons are made with the same structure designed with dissipative structural behaviour
PRELIMINARY EXPERIMENTAL TESTS ON STEEL-CONCRETE HYBRID COUPLED WALL SUBCOMPONENTS
No full textSingle-pier steel and concrete hybrid coupled walls are a dissipative seismic-resistant system composed of a single reinforced concrete central wall connected to two side columns through horizontal steel dissipative beams. Previous studies proved that the system is a viable alternative to the more common solution with two reinforced concrete coupled walls, but also highlighted some issues to be solved to enhance the global performance of the system. The present paper shows possible enhancements of the original system in which, to limit the cracking of the wall due to the bending force acting at the base, the base cross section is reduced and two vertical steel profiles are added. In this way, the wall transfers the shear forces to the foundation, while the bending moment is resisted mainly by the vertical steel profiles. Experimental tests were conducted to preliminary investigate the global and local behavior of the system and to highlight the possible benefits gained from the proposed original solution. In this paper, the numerical study behind the design of the tested prototype and the main experimental outcomes are discussed
PRELIMINARY EXPERIMENTAL TESTS ON STEEL-CONCRETE HYBRID COUPLED WALL SUBCOMPONENTS
No full textSingle-pier steel and concrete hybrid coupled walls are a dissipative seismic-resistant system composed of a single reinforced concrete central wall connected to two side columns through horizontal steel dissipative beams. Previous studies proved that the system is a viable alternative to the more common solution with two reinforced concrete coupled walls, but also highlighted some issues to be solved to enhance the global performance of the system. The present paper shows possible enhancements of the original system in which, to limit the cracking of the wall due to the bending force acting at the base, the base cross section is reduced and two vertical steel profiles are added. In this way, the wall transfers the shear forces to the foundation, while the bending moment is resisted mainly by the vertical steel profiles. Experimental tests were conducted to preliminary investigate the global and local behavior of the system and to highlight the possible benefits gained from the proposed original solution. In this paper, the numerical study behind the design of the tested prototype and the main experimental outcomes are discussed
Ductile design of single-pier steel and concrete hybrid coupled walls with hinged base and corner components
Get PDFThe seismic behaviour of hybrid coupled walls (HCWs) made of a single reinforced concrete (RC) wall connected to two steel side columns through steel links, named as single-pier HCWs (SP-HCWs), is studied through nonlinear finite element simulations. The design concept is that the steel links are intended to work as dissipative elements while the steel side columns and the RC wall should remain elastic. Given that previous studies highlighted difficulties in avoiding damage at the base of the RC wall due to the concentration of bending moment, this study focuses on a special configuration providing very limited damage at the base of the RC wall that could be rapidly and economically repaired. The original scheme of SP-HCW with fixed base is modified introducing a hinged connection combined with vertical steel elements, called corner components. A ductile design methodology is proposed and applied for proportioning 54 case studies with different building heights, coupling ratios, height-to-length ratios of the RC wall, in addition to different base conditions (fixed base, hinged base with corner components designed as non-dissipative elements, hinged base with corner components designed as dissipative elements). Results of nonlinear finite element analyses validate the design methodology and highlight the potentialities of the proposed solutions, showing the benefits of a hinged base with corner components
Preliminary study for reducing seismic damage in steel-concrete hybrid-coupled walls
Get PDFAn innovative single-pier hybrid coupled wall (SP-HCW), made of a single reinforced concrete wall coupled to two steel side columns by means of steel link, was recently proposed. The numerical analyses for this innovative solution showed the achievement of the designed seismic performances and the desired ductile global behaviour. However, the bottom zones of the concrete wall might experience undesired damages in case of strong seismic inputs. Hence, a new solution is presented and preliminary investigated, i.e., the wall is pinned at the base and equipped with additional vertical dissipative devices. This new configuration is expected to achieve no damage of the wall without reducing its dissipative capacity. In this article the results of preliminary pushover analyses are discussed to evaluate the expected performances of the proposed solution
The New Camerino University research center: Design of the base-isolated buinding and dynamic testing
No full textThis paper deals with the new Research Centre designed for the University of Camerino and entirely financed by the national Civil Protection Department (DPC), following the seismic events in Central Italy in 2016. The building consists of a base-isolated steel braced superstructure and r.c. sub-structures able to adapt to the complex morphology of the area. In particular, the first part of the paper illustrates the design choices made to achieve a high level of resilience and robustness of the building, i.e. to limit damage to structural and non-structural components and equipment under moderate and design seismic actions and to avoid disproportionate consequences in the event of extreme actions, larger than the design ones. The second part of the paper is focused on static and dynamic tests performed during the construction phase of the building. At the end of the structural system construction (including sub-structures, the isolation system composed by elastomeric bearings and flat sliders and the steel superstructure), the building has been tested by means of static and dynamic (snap-back) in-field tests up to a displacement of the isolation system of 280mm and 220mm, respectively. Displacements have been imposed by means of a properly designed testing mechanism and different measure instruments have been placed in the building to register the structural response
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Preliminary analyses of an innovative solution for reducing seismic damage in steel-concrete hybrid-coupled walls
Get PDFHybrid steel-concrete structures used as earthquake-resistant systems are an interesting solution for buildings in seismic prone areas, combining in effective ways the benefits of concrete and steel. In this context, an innovative single-pier hybrid coupled wall (SP-HCW), made of a single reinforced concrete wall coupled to two steel side columns by means of steel link, was recently proposed. The system is conceived to reduce the damage in the reinforced concrete wall while concentrating dissipation to the replaceable links. Although the numerical analyses for this innovative solution showed encouraging seismic performances and the desired ductile global behaviour, bottom zones of the concrete wall might experience undesired damages. Starting from the first proposed SP-HCW, in this study a new solution for its base is presented and preliminary investigated, i.e., the wall is designed as pinned at the base and equipped with additional vertical dissipative devices. In this way, this new configuration is expected to achieve lower damage of the wall without reducing its dissipative capacity. In this article the results of preliminary pushover analyses are discussed to evaluate the expected performances of the proposed structural solution
Variations on the Author
Get PDF“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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