Computational modelling of full interaction between crystal plasticity and oxygen diffusion at a crack tip

Oxidation-promoted crack growth, one of the major concerns for nickel-based superalloys, is closely linked to the diffusion of oxygen into the crack tip. The phenomenon is still not well understood yet, especially the full interaction between oxygen diffusion and severe near-tip mechanical deformation. This work aimed at the development of a robust numerical strategy to model the full coupling of crystal plasticity and oxygen diffusion in a single crystal nickel-based superalloy. In order to accomplish this, finite element package ABAQUS is used as a platform to develop a series of user-defined subroutines to model the fully coupled process of deformation and diffusion. The formulation allowed easy incorporation of nonlinear material behaviour, various loading conditions and arbitrary model geometries. Using this method, finite element analyses of oxygen diffusion, coupled with crystal plastic deformation, were carried out to simulate oxygen penetration at a crack tip and associated change of near-tip stress field, which has significance in understanding crack growth acceleration in oxidation environment. Based on fully coupled diffusion-deformation analyses, a case study was carried out to predict crack growth rate in oxidation environment and under dwell-fatigue loading conditions, for which a two-parameter failure criterion, in terms of accumulated inelastic strain and oxygen concentration at the crack tip, has been utilized

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

Meeting abstrac

An LFT Approach to

In this paper, a linear fractional transformation (LFT) approach is proposed in order to design a linear parameter-varying discrete-time $H_\infty$ controller including an anti-windup compensation. The provided methodology is applied to the control of diesel engine common rail injection systems. Simulation results on a non linear model are then shown and discussed. The control method is brie?y compared with the on-board gain-scheduled PID controller

Analyse du langage naturel par des techniques d'intelligence artificielle en vue de la constitution automatique de bases de données factuelles

National audienc

Solar radius measurements with the SODISM instrument : methods and algorithm developments for the PICARD Payload Data Center

International audienceThe PICARD space mission is scheduled for a launch in 2010. Its payload consists in 3 instruments: SODISM from LATMOS, SOVAP from IRMB (Belgium) and PREMOS from PMOD (Switzerland). SODISM key objective is to measure the diameter and shape of the Sun with an accuracy of a few milliarcseconds (mas), and their potential change during the increasing phase of the current solar cycle. We will present here some simulations and methods developed to make these measurements from SODISM images, and how these ones have been implemented at the PICARD Payload Data Center (PPDC) located at the B-USOC in Belgium

TAROT: Observing gamma-ray bursts "in progress”

The primary objective of the Télescope à Action Rapide pour les Objets Transitoires (TAROT - Rapid Action Telescope for Transient Objects) observatory is the detection of cosmic Gamma-Ray Burst sources at optical wavelengths while still active in Gamma-rays. It features a very rapid slewing mount, a 25 cm aperture telescope with a $2\times 2$ deg. fov, and is able to reach the 17th V magnitude in 10 s. A powerful scheduling algorithm, and an automated data processing system makes TAROT a fully autonomous facility. TAROT entered into service during the fall of 1998