170,164 research outputs found
Crack path and notch fatigue strength of Ti-6Al-4V ELI additively manufactured via selective laser melting: Defect sensitivity
No full textThe present work is aimed at exploring the applicability of the theory of critical distances (TCD) to the notch fatigue prognosis of the biomedical titanium Grade 23 (aka Ti-6Al-4V ELI) additively manufactured via selective laser melting (SLM). Particular attention is paid on investigating how the defectiveness influences the material critical length as well as the path followed by the fatigue cracks after nucleation. This latter aspect is of crucial importance, as the notch-crack equivalence postulated by TCD is reasonable only when the position selected for the critical point or the stress-averaging length reflects the actual path of the crack emanating from the notch tip. Specifically, fully-reversed axial fatigue tests are carried out on notched samples. Notches are either directly introduced into the samples via SLM or post-sintering machined via turning. The critical distance lengths are estimated according to critical distance inverse search procedure recently proposed by the authors (Santus et al., Int. J. Fatigue, vol.106 (2018) pp.208-218)
Experimental determination and sensitivity analysis of the fatigue critical distance obtained with rounded V-notched specimens
Get PDFThe critical distance inverse search procedure, recently proposed by the authors (Santus et al., 2018), was experimentally applied in this work to 42CrMo4+QT steel and 7075-T6 aluminium alloy for fatigue load ratios R = −1 and R = 0.1. The inverse search lengths were in good agreement with the critical distances derived from the crack threshold. The Point Method lengths were higher than the Line Method values since the relatively low stress distribution second derivative. However, this difference is compensated for when the corresponding Method, Point or Line, is then used for the fatigue strength assessment of another specimen or a component. The fatigue predictions and comparisons with the experiments are reported in an accuracy chart, showing that a small radius notched specimen is recommended to determine the critical distance and thus obtain an accurate strength assessment of a blunter specimen. This critical distance determination was then extended to the fatigue finite life, again obtaining accurate predictions, especially for the aluminium alloy. The online version of this paper is provided with MATLAB scripts which contain examples for the critical distance inverse search and the direct problem for the fatigue stress concentration factor calculation
The Roman Holy Office and the Christian East: Overview of Sources and New Research Perspectives
No full textIn this chapter I give an overview of the sources relating to Eastern Christianity in the archives of the Roman Inquisition. For several years, I have been conducting a systematic analysis of these sources, and I present some case studies to illustrate their significance and the importance of the documentation in Oriental languages that can be found there. On the other hand, I argue why it is important even for non-specialists to study the Inquisition’s attitude towards Eastern Christianity, insofar as it represented a challenge to the ecclesiological and disciplinary model of the Counter-Reformation, and by pointing out how the problems and difficulties raised by the spread of Catholicism in the East intersected with other controversies that shook the entire Catholic world in the seventeenth and eighteenth centuries
Introduction: Re-Orienting the History of Catholic Confessional Control
No full textThe text offers a historiographical review that highlights how, within the now substantial scholarship on the Inquisition and, more broadly, on Catholic global expansion in the early modern period, the Christian East has generally been neglected. This historiographical gap is striking, given that the archives of the various Inquisitions—especially those of the Roman Holy Office—contain extensive documentation on the confessional oversight exercised by the Catholic Church over Eastern Christianity, both in judicial matters (such as trials) and in doctrinal matters (dubia circa sacramenta, censures, etc). In addition to introducing the volume that aims to fill this historiographical gap, the essay also sets out to demonstrate the usefulness of such an approach. It argues that the long and complex formation of an “Eastern Catholicism” constituted a fundamental chapter in the history of early modern Catholicism tout court. Furthermore, it suggests that engagement with the Christian East furnished the Inquisition with a set of cultural tools and interpretive frameworks that were subsequently applied in other contexts, especially in missionary settings and in the broader theological controversies that shook the Catholic world from the seventeenth century onward
L’accoglienza e il controllo dei pellegrini orientali a Roma
No full textQuesto articolo ricostruisce la storia e il funzionamento dell’ospizio armeno di Santa Maria Egiziaca a Roma, formulando alcune considerazioni generali sul fenomeno della mobilità mediterranea dei cristiani orientali. A partire dalla fine del XVI secolo, infatti, un numero crescente di sudditi ottomani o persiani visitò la capitale della cattolicità, per ragioni devozionali, educative o economiche. Questo movimento, finora poco studiato, provocò ovviamente la reazione delle autorità cittadine ed ecclesiastiche, preoccupate di controllare il flusso dei visitatori e di garantire la purezza dell’ortodossia di quanti risiedevano più o meno temporaneamente nell’Urbe.This article reconstructs the history and functioning of the Armenian hospice of Santa Maria Egiziaca in Rome (Surb Mariam Egiptac‘i), also formulating some general considerations on the mobility of Eastern Christians across the Early Modern Mediterranean. Since the end of the 16th century, a growing number of Ottoman and Persian subjects visited the center of Catholicism, for devotional, educational or economic reasons. This hitherto little studied movement provoked the reaction of the urban and ecclesiastical authorities, concerned with managing the flow of visitors and controlling the orthodoxy of those who resided more or less temporarily in Rome
Initial orientation of the fretting fatigue cracks in shrink-fit connection specimens
Get PDFThe bending configuration of shrink-fitted connection fretting fatigue tests causes a fluctuation of the contact pressure and in turn a more favourable condition for shear, rather than tensile, crack initiation. According to the classification Type I (shear) and Type II (tensile) fretting cracks, the type II was only observed for the tests with no surface enhancement, which experienced the lowest fretting strength and then a reduced pressure fluctuation effect. The crack initial direction was predicted as the critical plane orientation undergoing the maximum FS stress parameter, for the shallow type I shear cracks. If the critical plane is searched at the fretting hot-spot, the incorrect outward direction is obtained, since the orthogonal direction, with the same shear stress amplitude, experiences a more compressive maximum normal stress. On the contrary, with the application of the Point Method, taking the stress location at half the critical distance and by following the potential critical plane, a higher shear stress along the inward direction is obtained. The more compressive stress below the contact can therefore be compensated, and then the inward shallow direction is correctly predicted
La comunità armena di Costantinopoli all'inizio del XVIII secolo: scontri e tentativi di accordi interconfessionali (XVIII sec.)
No full textDurante il XVII e il XVIII secolo, la pratica della "communicatio in sacris" era particolarmente diffusa nell’Impero ottomano, in seguito ai successi dei missionari nella conversione delle comunità cristiane locali. Gli Armeni di Costantinopoli e delle province orientali furono particolarmente interessati dal fenomeno, che assunse presto dimensioni problematiche. Non essendo allora gli Armeni cattolici riconosciuti come comunità autonoma o separata da quella dipendente dal Patriarca nominato dal Sultano, i convertiti erano in ogni caso costretti a recarsi dal clero apostolico per tutti quegli atti religiosi che rivestivano carattere civile o ufficiale: quanti si rifiutavano potevano essere considerati ribelli anche da un punto di vista politico e questo scatenava dure persecuzioni. Lo studio dei tentativi intrapresi a Costantinopoli nei primi decenni del ‘700 per regolare i rapporti tra Armeni cattolici e apostolici mostra però come alle fratture religiose si sovrapponessero anche altre dinamiche politiche ed economiche, legate in particolare al ruolo giocato dall’ambasciata di Francia, dalle autorità ottomane e dai missionari e mercanti europei
A proposito di «D'Alep à Paris. Les pérégrinations d'un jeune syrien au temps de Louis XIV»
No full textRecension
Les papiers des consulteurs. Questions missionnaires et procès de décision au Saint-Office, XVIIe‐XVIIIe siècles
No full textLes années entre la fin du XVIIe siècle et le début du XVIIIe siècle ont été témoins d’une vaste controverse mettant en question les conditions de possibilité d’un catholicisme adapté aux territoires de mission au Proche, Moyen et Extrême-Orient. Il ne s’agit pas seulement des querelles des rites chinois et malabares, mais aussi du problème des relations entre catholiques et orthodoxes dans l’Empire ottoman. Dans la discussion de ces questions, on se focalise normalement sur les acteurs les plus visibles – les missionnaires sur le terrain – en oubliant les protagonistes cachés et silencieux de cette histoire : les docteurs et bureaucrates romains qui avaient la charge d’examiner et de résoudre les dubia des religieux. Cet article se focalise justement sur le rôle des consulteurs du Saint-Office et en particulier sur leurs archives, dans l’effort de mieux comprendre le processus de prise de décision au sein de l’Inquisition romaine
La communicatio in sacris con gli «scismatici» orientali in età moderna
No full textNel Levante di età moderna la communicatio in sacris tra cristiani orientali e cattolici era una realtà ovunque diffusa e consolidata. Il tentativo romano di inquadrare e disciplinare questo fenomeno diede il via ad una vera e propria battaglia di idee, che finì per toccare il problema di definire più chiaramente cosa fossero gli « scismatici » orientali e come dovessero venire trattati. Sulla base di quali argomenti poteva essere lecita o illecita la frequentazione delle cerimonie e dei sacramenti degli acattolici? Le opinioni prese in considerazione spazieranno dalla manualistica canonica e missionaria alle relazioni con cui i religiosi stessi giustificavano il loro operato, fino ad arrivare agli elaborati voti con cui i consultori del Sant’Uffizio provarono a governare l’intricata materia
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