1,721,042 research outputs found
Dissipative and thermal aspects in cyclic loading of additive manufactured AISI 316L
Get PDFThis study presents a comprehensive understanding of the fatigue behavior of 316L stainless steel specimens produced using the laser powder bed fusion (PBF-LB/M) method. The
investigation has been conducted through a multifaceted approach that includes surface
roughness analysis, density measurements, microstructural examination, fatigue testing, strain
measurements, and thermographic analysis. Thermographic data processing models, i.e. the bipower law (TCM-modified) model and the TCM method, are applied to fatigue test results of
standard samples to evaluate fatigue limit values. The fatigue limit of the samples was estimated
using the Murakami Method (MM), Constant Amplitude Loading (CAL) and Step Loading (SL)
tests. The proposed methodology allows exploration of the entire stress level range within a
single test, which could allow evaluation of the fatigue limit of components within only one
test. This study is the starting point for a rapid evaluation method for estimating the fatigue
limit using thermography, offering a cost-effective, time-efficient, and non-destructive means of
assessing the fatigue performance of materials produced using additive manufacturing processes
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
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
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Get PDFWe 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
Beitrag zur Anwendung der Bohrlochmethode zur Bestimmung von Lastspannungen an Gussstützen im Bestand
No full textDie Bohrlochmethode wurde angepasst zur Lastspannungsbestimmung an historischen Gussstützen im Bestand. Hierfür wurde ein Hochgeschwindgkeitsfräser entwickelt, eine Methode zur Korrektur kleiner Bohrexzentrizitäten wurde entwickelt und der Einfluss einer über die Bauteildicke nicht konstanten Spannung wurde betrachtet
Fracture Mechanics Based Approach to the Significance of Certain Loads on the Service Life of Rails
No full textAbstractIn this paper, the fatigue design of rails in the transition from bridge to abutment is examined. The current fatigue design of rail systems is carried out with simplifying assumptions concerning the stresses in the rail. Thus, the determination of a fatigue endurance limit is done with stresses based on the Smith-Diagram. By applying this means of design, the assumption is made that there are mainly normal stresses in a rail. Those may originate from changes in temperature, accelerating or slowing down of the trains as well as bending stresses caused by the passing of trains. Horizontal components of the load (from the train's sine run, lateral shift of bridges or the cant of curves) are not considered in this design format.At the same time, specimens in fatigue tests with pulsing vertical loads regularly show unexpected and inexplicable cracks at the edge of the rail foot and a huge scatter of the results. In cases of rail breaks the location of the incipient crack is not necessarily in the cross section's area with the largest tensile stresses, but can be shifted to areas of smaller tensile stress (e.g. the edge of the rail foot).Obviously additional criteria such as the condition of the surface of the rail foot in combination with stresses from warping of the section (secondary bending) have more influence on the fatigue performance than estimated before.This paper presents an approach to evaluate the importance and priorities of the named influencing factors and criteria on the fatigue design of rails by means of fracture mechanics. The focus hereby lies on the rail foot, since in this region of the cross section there are no disturbing influences as contact problems or wear
- …
