1,720,964 research outputs found
Investigation into metal wire based variant of EMI technique for structural health monitoring
No full textElectro mechanical impedance method (EMI) is a newly non-destructive evaluation method which is becoming very famous in the field of structural health monitoring. In this article a new approach is being proposed to effectively detect the initiation and progression of structural damage by the global dynamic electro-mechanical impedance (EMI) techniques. In this context the PZT patches are being used to determine the natural frequency and the strain mode shapes and the electro mechanical admittance signature to facilitate an improved damage assessment. Nowadays the safety issues for the case of composite building materials are getting more importance. The main problem of using EMI method is its brittleness so to overcome from this problem we are using this method by coupling a metal wire with a PZT element. In this method we created progressive damages and deterioration scenarios and we evaluated with the application of the proposed metal wire EMI method
Recent developments in metal wire based electro-mechanical impedance technique for structural health monitoring
No full textThis paper presents an overview of the recent experimental and numerical developments in the field of metal wire based electro-mechanical impedance (MWBEMI) technique for the purpose of structural health monitoring (SHM). MWBEMI approach is a new variant of the EMI technique and has specific advantages, which makes it a preferred technique for certain ceramics and inaccessible locations of the structure. This paper summarizes the experimental investigations for studying the practical aspects of the technique. It then describes a new algorithm for damage localization in 2D structures using minimum number of sensors. The overall results demonstrate strong potential of the MWBEMI approach for improved SHM
Metal-wire-based twin one-dimensional orthogonal array configuration of PZT patches for damage assessment of two-dimensional structures
No full textThis article presents a new field-deployable algorithm harnessing the metal-wire-based variant of the electro-mechanical impedance technique, warranting drastically lesser number of piezo sensors, for damage detection and localization on large two-dimensional structures such as plates. The metal-wire-based approach is a new variant of the electro-mechanical impedance technique. Although less sensitive than the conventional electro-mechanical impedance technique, it is a panacea in situations where direct bonding of lead zirconate titanate (PZT) patches on the host structure is not possible, such as inaccessible structural locations, parts under continuous impact from external loads, brittle materials (triggering signatures without any peaks) or high-temperature locations. This article first reports detailed experimental investigations into the practical aspects of the metal-wire-based electro-mechanical impedance technique. These cover the effect of various associated parameters, such as the wire cross-section, shape, discontinuity and other related issues. Repeatability of signature is also investigated along with the effect of possible breakage in the wire and inadvertent bending. The technique is further adapted by replacing the wire by a thin foil, which is found to improve the damage sensitivity substantially. The proposed algorithm for damage localization on two-dimensional structures uses the PZT patches in the metal-wire-based orthogonal twin-array configuration. The metal-wire-based electro-mechanical impedance technique is first simulated through finite element method, coupled with the basic impedance model, to test the algorithm on the numerical model of a mild steel plate, 1200 mm×970 mm×8 mm in size. The algorithm is then validated through full-scale test on the actual plate, covering damage at various locations. The developments of this article shall pave way for practical application of the metal-wire-based electro-mechanical impedance technique on large two-dimensional structures with minimum number of sensors, especially in situations where the direct electro-mechanical impedance technique is not feasible to be used.</p
Virtual smart structures and dynamics lab: towards teaching advanced concepts online
No full textThis paper presents an overview of the Virtual Smart Structures and Dynamics Lab (VSSDL) at the Department of Civil Engineering, IIT Delhi. VSSDL has been set up as a part of the ‘Virtual Labs’ project sponsored by the Ministry of Human Resource Development (MHRD), Government of India, under the National Mission on Education through Information and Communication Technology (NMEICT). The aim of the lab is to be emerge as an effective medium of learning for those students who do not have access to specialized lab in the area of smart materials and structures or those who wish to take up and R&D career in this field. The lab covers experiments concerning interdisciplinary applications of smart materials and structures concerning structural dynamics. The lab provides two types of experiments- trigger based and simulation based, both of which can be effectively used for learning purposes. Students from all over the world can take advantage of the facilities to master advanced concepts thorough online experiments of VSSDL
Multi-disciplinary applications of piezo-sensors: structural health monitoring, bio-mechanics and energy harvesting
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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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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