1,720,964 research outputs found
Analysis of linear elastic masonry-like solids subjected to settlements
No full textA linear elastic no-tension material model is implemented in this contribution to cope with
the analysis of masonry-like solids in case of either elastic or inelastic settlements. Instead of implementing
an incremental non-linear approach, an energy-based method is adopted to address the
elastic no-tension equilibrium. Under a prescribed set of compatible loads, and possible enforced displacements,
a solution is found by distributing an equivalent orthotropic material having negligible
stiffness in tension, such that the overall strain energy is minimized and the stress tensor is negative
semi-definite all over the domain. A preliminary implementation of the proposed method is given
by adopting a heuristic approach to turn the multi-constrained minimization problem into an unconstrained
one. Numerical simulations focus on a wall with an opening subjected to either inelastic
settlement or standing on elastic soil
Numerical Analysis of Mechanical Damage in Ribbed Masonry Vaults under Differential Settlements
No full textThe present study takes advantage of a parametric model, which allows one to create automatically complex structural models of ribbed masonry vaults. Two numerical modelling strategies are discussed: a 3D continuum and a 3D contact-based model. The effects of settlements are studied by imposing vertical displacement at the vault supports up to collapse. Predictions of each modelling strategy are compared with actual damage observation. A representative square vault of Milan Cathedral is studied here, aiming to understand the causes of the damage documented through the years. The structure is noted to have suffered structural damage in the vaulting system due to a long history of soil settlements. The geometry is based on a photogrammetric scanning, and the three-dimensional solid models are created through parametric reconstruction procedures, including details such as springing, arch, ribs, web, and rubble-fill. Both modelling strategies allow to highlight the vulnerability of masonry vaults due to settlements. Significant differences in prediction capabilities are noted when large displacements and separation of elements are involved. The simulations show the possibility of predicting and interpreting different complex damage phenomena as arch block damage or sliding, and web–arch detachment, which is frequently observed in historical structures
Advances in cultural heritage studies
No full textThe announcement of the creation of a European Year of Cultural Heritage (year 2018) by the Decision 2017/864 of the European Parliament – encouraged the creation, in 2017, of the European Students’ Association for Cultural Heritage (ESACH) ESACH has become the first still-growing interdisciplinary and cross-generational network in the field. Currently brings together young researchers and researchers at early stages of their careers, in the fields of culture and heritage, from all kinds of academic disciplines and is made up of members from various European universities and research centres (see www.esach.org).
Within the network, the main questions are: How do we engage with the past elements of our culture(s)? How and why do we protect culture as a genuine element of a contemporary cultural system? What do younger generations state as heritage and what ways do they see to safeguard and experience it? ESACH stands up for a participatory way of involvement and is eager to take part in the cultural discourse at European and national levels.
Since ESACHS’ foundation, the Portuguese publisher Mazu Press (www.mazupress.com) has been associated with the initiatives of the Portuguese branch of ESACH based in Lisbon (Sharing Heritage Lisbon), firstly with the promotion actions and then with the publication of the book “New Perspectives in Interdisciplinary Cultural Heritage Studies. Contributions of the European Students’ Association for Cultural Heritage in the European Year of Cultural Heritage 2018”.
In this atypical Covid-19 pandemic year, Mazu Press again invited ESACH to join the renewed idea of “unifying through Cultural Heritage”, creating the opportunity for all to associate their efforts to this volume of “Advances in Cultural Heritage Studies, Year 2020”. Until now, ESACH members have been given the opportunity to contribute their ideas in several European events organized by the respective stakeholders, such as the Genoa Meeting, in October 2019, which had the cultural, logistic and financial support of the University of Genoa and foremost the PhD Course in Study and Enhancement of the Historical, Artistic-Architectural and Environmental Heritage. This book brings together twenty chapters by twenty four authors from Canada, Greece, Ireland, Italy, Poland, Portugal, Slovakia, Spain and Turkey. This sharing of knowledge, culture and heritage studies, through various disciplines, shows the richness – advances and new perspectives – generated by the common passion for cultural heritage
Considerations about the static response of masonry domes: A comparison between limit analysis and finite element method
No full textMasonry domes constitute a large part of the international architectural heritage. The issue of its conservation has long been a challenge both for architects and engineers. To limit any problems related to degradation, arising from structural damage or external factors, historical buildings are continuously restored and strengthened. Reliable tools are therefore needed to assess their structural safety. The present work discusses how modern methods can be used to understand ancient structures addressing the comparison between different methods of structural analysis, exploring the range of applications of limit analysis and finite element analysis in the stability assessment of masonry domes, focusing on the pros and cons of each approach. By applying equilibrium approaches and deformation-based models (finite element method), this paper provides two demonstration examples to compare the utility of each of them within a longstanding debate on the most proper way to evaluate traditional structures in masonry
Structural assessment of iron tie rods based on numerical modelling and experimental observations in Milan Cathedral
No full textIron ties contribute to the stability of structural systems having vaults and arches. The axial force in the iron ties is not easily to be measured but this knowledge is important for assessing the safety of these members. In the case of breakage of iron tie rods, the assessment study needs to understand the causes of the failures. Experimental data are collected, and models are used for their interpretation. The aim of this paper is to propose a new integrated experimental and numerical approach for the structural analysis of tie rod tensions in historical buildings. The study considers an application at Milan Cathedral, where recently some iron tie failures were observed. The collected data taken into account are: (a) Point cloud measurement of the geometry (b) Understanding of construction phases, (c) Soil-settlement measurement in the last 50 years, (d) Experimental measurement of the iron ties axial force, and (e) Documentation of damage and iron tie failures in the last century. It is here proposed to use an advanced numerical model for simulating, interpreting and predicting the measured response of the iron ties. The finite element numerical model includes detailed geometry of elements, material properties of masonry based on texture observations and iron ties modelling. The paper shows how the actual structural configuration, the choices on material properties, the consideration of construction stages or load history and soil settlements affect the tension state in the iron ties. In particular, it is demonstrated through the carried-out analysis the possibility to correlate the tension force in the ties with soil settlements. Finally, the developed numerical model can be used also during practical maintenance operations of iron tie replacement, by predicting the stressed state, the possible lateral displacements of the pier and the associated structural safety
DIGITAL MODELLING AND ANALYSIS OF MASONRY VAULTS
Full text linkThe focus of this paper is to discuss the peculiarities of the digital modelling of masonry cross vaults. The proposed methodological approach for a multidisciplinary study of masonry vaults will be focused on: geometrical survey, crack pattern, geometrical modelling, and safety assessment based on structural analysis.Automatic reconstruction procedures recently proposed in the literature for ribbed masonry vaults, are used to overcome time-consuming modelling tasks. The created digital models take into consideration the different aspects of the three-dimensional geometry, the internal divisions with variations of material properties in different parts, and a suitable discretization for finite element analysis. Moreover, the same model can be used in BIM (Building Information Modelling), judged as a suitable environment in which to combine different aspects of the restoration works such as: documentation, intervention design, and the data system in an unique model. The same model is then used to perform finite element analysis. Each of these aspects is clarified with examples of different vaults typology coming from case studies as that of the church of St. Bassiano in Pizzighettone (Cremona) or the notable Milan Cathedral.</p
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
- …
