Micromechanical investigation of the influence of defects in high cycle fatigue

This study aims to analyse the influence of geometrical defects (notches and holes) on the high cycle fatigue behaviour of an electrolytic copper based on finite element simulations of 2D polycrystalline aggregates. In order to investigate the role of each source of anisotropy on the mechanical response at the grain scale, three different material constitutive models are assigned successively to the grains: isotropic elasticity, cubic elasticity and crystal plasticity in addition to the cubic elasticity. The significant influence of the elastic anisotropy on the mechanical response of the grains is highlighted. When considering smooth microstructures, the crystal plasticity have has a slight effect in comparison with the cubic elasticity influence. However, in the case of notched microstructures, it has been shown that the influence of the plasticity is no more negligible. Finally, the predictions of three fatigue criteria are analysed. Their ability to predict the defect size effect on the fatigue strength is evaluated thanks to a comparison with experimental data from the literature

Quand Madelon : Chanson - Marche

https://digitalcommons.library.umaine.edu/mmb-ps/3604/thumbnail.jp

When Madelon

https://digitalcommons.library.umaine.edu/mmb-vp/5559/thumbnail.jp

Simplified numerical approach for incremental sheet metal forming process

The current work presents a finite element approach for numerical simulation of the incremental sheet metal forming (ISF) process, called here ‘‘ISF-SAM’’ (for ISF-Simplified Analysis Modelling). The main goal of the study is to develop a simplified FE model sufficiently accurate to simulate the ISF process and quite efficient in terms of CPU time. Some assumptions have been adopted regarding the constitutive strains/stresses equations and the tool/sheet contact conditions. A simplified contact procedure was proposed to predict nodes in contact with the tool and to estimate their imposed displacements. A Discrete Kirchhoff Triangle shell element called DKT12, taking into account membrane and bending effects, has been used to mesh the sheet. An elasto-plastic constitutive model with isotropic hardening behaviour and a static scheme have been adopted to solve the nonlinear equilibrium equations. Satisfactory results have been obtained on two applications and a good correlation has been shown compared to experimental and numerical results, and at the same time a reduction of CPU time more than 60% has been observed. The bending phenomenon studied through the second application and the obtained results show the reliability of the DKT12 element

A comparison between different methods for the numerical simulation of polycrystalline aggregates

The macroscopic behavior of polycrystalline materials is largely influenced by the shape, the arrangement and the orientation of crystallites. Different methods have thus been developed to determine the effective behavior of such materials as a function of their microstructural features. In this work, which focuses on polycrystalline materials with an elastic-viscoplastic behavior, the self-consistent (SC) method [1], the finite element (FE) method and the spectral (FFT) method [2] are compared. These common methods are used to determine the effective behavior of different 316L polycrystalline aggregates subjected to various loading conditions (uniaxial tension, cyclic tension/compression).(...

Identifying Attrition Phases in Survey Data: Applicability and Assessment Study

Background: Although Web-based questionnaires are an efficient, increasingly popular mode of data collection, their utility is often challenged by high participant dropout. Researchers can gain insight into potential causes of high participant dropout by analyzing the dropout patterns. Objective: This study proposed the application of and assessed the use of user-specified and existing hypothesis testing methods in a novel setting—survey dropout data—to identify phases of higher or lower survey dropout. Methods: First, we proposed the application of user-specified thresholds to identify abrupt differences in the dropout rate. Second, we proposed the application of 2 existing hypothesis testing methods to detect significant differences in participant dropout. We assessed these methods through a simulation study and through application to a case study, featuring a questionnaire addressing decision-making surrounding cancer screening. Results: The user-specified method set to a low threshold performed best at accurately detecting phases of high attrition in both the simulation study and test case application, although all proposed methods were too sensitive. Conclusions: The user-specified method set to a low threshold correctly identified the attrition phases. Hypothesis testing methods, although sensitive at times, were unable to accurately identify the attrition phases. These results strengthen the case for further development of and research surrounding the science of attrition

Madelon (I\u27ll be true to the whole regiment) : song

https://digitalcommons.library.umaine.edu/mmb-vp/2059/thumbnail.jp

Création d’un programme de réhabilitation à la marche avec utilisation de la double-tâche en neurologie: une scoping review et une validation d’experts

Les troubles neurologiques touchent à ce jour des millions de personnes dans le monde et ont pour conséquences diverses atteintes motrices et/ou cognitives : la marche est une des activités fréquemment affectée. Aucune étude n’a encore été réalisée sur la rééducation de la marche à l’aide de la double-tâche pour l’ensemble des maladies neurologiques. Notre travail comporte deux objectifs : 1) analyser les effets d’un entraînement basé sur la double-tâche pour rééduquer la marche chez des patients ayant des pathologies neurologiques variées, 2) créer un programme progressif et adapté en prenant les exercices des études sélectionnées

Sacrée, l’égalité hommes-femmes ?

Tout comme la France, le Québec a connu d’importants débats sur la laïcité au cours des dernières années. Dans ce contexte, une certaine lecture de l’histoire des femmes et le principe d’égalité entre les sexes ont été utilisés comme arguments pour justifier la mise en place de politiques ciblant particulièrement certains signes religieux, dont le hijab. Or, est-il exact d’affirmer que, historiquement, c’est essentiellement « la religion » qui aurait causé l’oppression des femmes ? Est-ce juste de présumer que, conséquemment, la laïcité garantirait une amélioration de leur condition ? En m’appuyant sur l’histoire des femmes à plusieurs moments de « modernisation » et de « laïcisation » au Québec, je propose de remettre en question ce postulat central aux discours en faveur d’une laïcité républicaine.In Quebec, like France, secularity has been the object of significant debate over recent years. In this context, a certain reading of women’s history and the principle of gender equality have been used as arguments to justify the implementation of policies targeting certain religious symbols, such as the Hijab. But is it correct to state that, historically, “religion” is what is primarily responsible for women’s oppression? Is it fair to assume, consequently, that secularization would guarantee an improvement in women’s situation? Drawing on the history of women at several points in the processes of “modernization” and “secularization” in Quebec, I question this central premise of discourses in favour of state secularity