1,721,018 research outputs found
Analysis and control of façade claddings structural issues
No full textAlthough closely related with the building structure and required to possess adequate resistance to the acting loads too, the new cladding systems have shown not infrequently inconsistencies or mechanical deficiencies, such as to compromise their safety. The paper shows the necessity of studying and solving the structural aspects of façade claddings through proper numerical modelling and laboratory test, defining a systematic methodology for the evaluation of the structural aspects of the façade cladding that can be used both in case of new construction and building refurbishment
Aspetti strutturali dei rivestimenti di facciata
No full textThe building sector is today more and more often represented by tall, complex, energy-efficient and multi-functional buildings, characterized by innovative façade systems. The recent history teaches that, although closely related with the building structure and required to possess adequate resistance to the acting loads too, the new cladding systems have shown not infrequently inconsistencies or mechanical deficiencies, such as to compromise their safety. This for a competency gap between structural engineers, inclined to consider the façades only as an additional mass carried by the structure, and building designers, interested to deepen the technological and detail aspects related to appearance, energy, acoustic and durability performance, but not related to behaviour and safety under the stresses and deformations point of view. Overlook or underestimate the structural aspects in the façade design can result in critical consequences, especially in the case of large buildings subject to seismic and wind actions. This paper calls and illustrates the necessity of studying and solving the structural aspects of façade claddings through proper numerical modelling and laboratory tests
Life-cycle structural assessment of industrial heritage buildings
No full textThe industrial complex of cast iron foundries located in Multedo (Genoa, Italy) was established in 1917 and represents a remarkable example of industrial archaeology. The factory is not in use since many years and its buildings, mostly made by reinforced concrete structures, are severely damaged by aging and deterioration processes, mainly related to chloride induced corrosion of the reinforcing steel bars. The feasibility of a reuse of the industrial complex has been investigated through experimental tests and numerical analyses. This paper summarises the main results of such activity, with emphasis on the life-cycle assessment carried out to describe the chloride diffusion process, the effects of reinforcing steel corrosion, the time-variant loss of structural performance and the consequent reduction of structural safety
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
Flexural models of reinforced concrete beams under blast load
Full text linkNowadays, the issue of structural safety under blast loading has become a dramatic problem. The tragic news
of the terrorist attacks of recent years (9/11/2001, New York; 7/7/2005, London; 7/23/2005, Sharm El Sheik;
1/24/2011, Moscow; etc), raise important, urgent questions regarding the real safety and reliability of our buildings. Extreme loads such as impacts, explosions, etc., can occur in everyday life with unexpectedly high frequency. Actually, the problem of terrorist attacks, so important for strategic and military building design, has been linked to residential and industrial building explosion accidents. The present thesis deals with the flexural failure of Reinforced Concrete beams under blast loads. The main aim is firstly to develop dynamic and energy models capable of evaluating the response of R.C. under explosive load. Then a sensitivity analysis is obtained by means of the above mentioned models in order to determine what are the key
parameters in the beam response. In this way it is possible to attain simple predictive polynomial formulations and, finally, simple table for early structural assessment of beams under blast load during the design procedure.
The thesis is composed of three sections. Various dynamic models are developed in Section 1, taking into
account the strain-rate sensitivity of both steel and concrete, as well as other nonlinearities in structural
behaviour. Models with different levels of complexity are presented, from the simplest Single Degree Of
Freedom (SDOF) system to Continuous Beam and Finite Element models. The characteristics, advantages and disadvantages of each approach are stated and discussed. The author compares his models with some experimental findings available in the scientific literature. The principal innovation that can be inferred from this section is the hypothesis of distributed plasticity along the beam (in the continuous model), represented by a non-linear smooth relationship between bending moment and curvature. This relationship, in addition to the Euler-Bernoulli beam equation, yields a non-linear Partial Differential Equation solved by means of the Finite Difference Method. In Section 2, the same problem is solved in a different way: starting from the principle of energy conservation, the innovative procedure, developed by the author, can calculate the displacement field of a R.C. beam under blast load. This procedure, less accurate than the previous one, produces very good results regarding midspan displacement, especially as it requires less computation time.
In order to better understand the phenomenon, with the aim of identifying the key parameters in structural response, a sensitivity analysis is developed in Section 3. To this end, the author has performed a numerical investigation referring to the SDOF model presented in Section 1. Several numerical simulations are performed, with random variation of beam and load characteristics. Results are expressed in terms of maximum deflection and maximum velocity for each case. Then a least-squares interpolation has produced
various polynomial curves and surfaces representing both a simplified tool to estimate structural response and a sensitivity analysis of the key parameters involved. One of the possible developments of this useful work is represented by simple tables that provide the response of the beam under blast load for early assessment in design procedures
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
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