BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Institut de Recherche en Génie Civil et Mécanique - ECPv6.2.8.2//NONSGML v1.0//EN CALSCALE:GREGORIAN METHOD:PUBLISH X-WR-CALNAME:Institut de Recherche en Génie Civil et Mécanique X-ORIGINAL-URL:https://gem.ec-nantes.fr X-WR-CALDESC:évènements pour Institut de Recherche en Génie Civil et Mécanique REFRESH-INTERVAL;VALUE=DURATION:PT1H X-Robots-Tag:noindex X-PUBLISHED-TTL:PT1H BEGIN:VTIMEZONE TZID:Europe/Paris BEGIN:DAYLIGHT TZOFFSETFROM:+0100 TZOFFSETTO:+0200 TZNAME:CEST DTSTART:20170326T010000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:+0200 TZOFFSETTO:+0100 TZNAME:CET DTSTART:20171029T010000 END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTART;TZID=Europe/Paris:20170330T140000 DTEND;TZID=Europe/Paris:20170330T140000 DTSTAMP:20240328T182008 CREATED:20170328T115805Z LAST-MODIFIED:20170328T115805Z UID:2696-1490882400-1490882400@gem.ec-nantes.fr SUMMARY:Séminaire GeM - Charbel-Pierre EL SOUEIDY "Recent Developments in Metamodeling Techniques for Time-Variant Reliability Analysis" DESCRIPTION:  \nPrésentation : Charbel-Pierre EL SOUEIDY\, équipe TRUST\nInvitation : Equipe MEO \nM. Charbel-Pierre EL SOUEIDY\, membre du GeM au sein de l’équipe TRUST donnera un séminaire le 30 mars 2017 à 14h00 à Centrale Nantes (Amphi A). \nCe séminaire portera sur la méta-modélisation en particulier pour les phénomènes dépendant du temps (dégradation\, endommagement) et en présence d’incertitudes\, intéressera\, nous l’espérons\, le plus grand nombre. Ce sujet a fait l’objet d’une présentation en 2016 par Lara Hawchar en finale inter-régionale de la thèse en 180 secondes MT180. \n\n  \nRecent Developments in Metamodeling Techniques for Time-Variant Reliability Analysis\nRésumé : \nTime-variant reliability analysis is a challenging task in practical engineering applications. It aims to evaluate the probability that a structural system successfully performs its intended function throughout its service life. Time dependent uncertainties\, such as dynamic loadings and deterioration in material properties\, are usually described as stochastic processes whose discretization may lead to a significant number of truncated terms (i.e. the input variables) leading to the curse of “dimensionality”. A second challenging issue in time-dependent reliability analysis is that it usually requires the computation of the extreme value of the limitstate function over the structure lifetime. The extreme value function may be highly nonlinear and follow multimodal distribution. Traditional reliability methods\, such as FORM may produce large errors whereas simulation methods such as the Monte-Carlo simulation (MSC) can be prohibitively time-consuming. \nIn this talk\, two Polynomial Chaos (PC)-based approaches for time-variant reliability analysis are proposed. The former method relies on the Principal Component Analysis (PCA). First\, the time interval of study is discretized and an instantaneous performance function is associated to each time node. Then\, a principal component analysis is performed in order to represent all these functions with a reduced number of components. A PC expansion is next used to approximate each of these components. The latter method is based on the Efficient Global Optimization (EGO) approach. Considering a reduced experimental design\, the maximum value of the performance function for each realization is first obtained performing EGO. The obtained set of maxima is then used to approximate the extreme value function with PC by means of a non-intrusive regression scheme. In both cases\, a surrogate model of the response is obtained on which classical simulation-based techniques such as the MCS can be implemented for an easy evaluation of the time-dependent probability of failure. \nThe proposed approaches are compared with some recent time-dependent reliability analysis methods. Non-linear time-dependent limit state functions of both non-Gaussian and nonstationary processes are considered. The accuracy and efficiency of the proposed approaches are demonstrated in all cases. \n  URL:https://gem.ec-nantes.fr/event/seminaire-gem-charbel-pierre-el-soueidy-recent-developments-in-metamodeling-techniques-for-time-variant-reliability-analysis/ LOCATION:Ecole Centrale Nantes – Amphi A\, 1\, rue de la noe\, Nantes\, France CATEGORIES:Séminaires END:VEVENT END:VCALENDAR