Mise en place d’une démarche qualité au LARMAUR

National audiencePoster: Implementation of a quality approach in LARMAURThe growth of research activities and human resources of the LARMAUR, has led the direction of the laboratory to initiate a quality approach in January 2012. The main objective was to optimize the organization and the running of the research unit. The quality policy is covering: the reorganization of the laboratory (research topics, work groups, operating mode), the optimization of organization, operation and management of experimental devices and the optimization of scientific and technical research performed in the laboratory. To get buy-in with the quality approach, it was decided to give to the "proof of concept". The approach was implemented on an experimental device working closely with the team. Once the concept has been validated by the laboratory council, a quality manager has been appointed, and the project has been extent to the whole laboratory considering the small size of the research unit.More information: http://www.larmaur.univ-rennes1.frKeywords: research, management, optimization, process, qualityPoster : Mise en place d’une démarche qualité au LARMAURFort de la dynamique croissante des activités et des ressources humaines du LARMAUR, une démarche qualité a été initiée par la direction en janvier 2012 afin d’optimiser l’organisation et le fonctionnement de l’unité. La politique qualité mise en place par la direction concerne : la réorganisation du laboratoire (thèmes de recherche, groupe de travail, mode de fonctionnement), l’optimisation de l’organisation, du fonctionnement et de la gestion des dispositifs expérimentaux et la valorisation des travaux scientifiques et techniques réalisés au sein du laboratoire.Afin de remporter l’adhésion de l’unité sur cette démarche, il a été décidé de passer par la « preuve du concept » en appliquant la démarche sur un dispositif expérimental dont l’équipe associée était convaincue de l’intérêt. A l’issue d’une présentation des résultats obtenus en conseil de laboratoire, un responsable qualité a été nommé, et le projet a été étendu à l’ensemble du laboratoire en s’adaptant aux besoins d’une unité de recherche de petite taille.En savoir plus : http://www.larmaur.univ-rennes1.frMots clés : recherche, organisation, valorisation, processus, qualit

Institut de Physique de Rennes La démarche qualité au sein du Département Mécanique et Verres

International audienceInstitut de Physique de RennesLa démarche qualité au sein du Département Mécanique et VerresMariette NIVARD1, Jean-Christophe SANGLEBOEUF2Depuis plusieurs années, le LARMAUR ERL 6274 du CNRS, est une unité de recherche qui s’inscrit dans une dynamique de croissance, tant en ressource humaine qu’en projets scientifiques. A l’occasion de la dernière évaluation AERES, les tutelles ont souhaité une intégration à mi-parcours de cette unité au sein de l’IPR3 (effectif depuis janvier 2014). La direction du LARMAUR a saisi cette occasion pour initier une démarche qualité et revoir l’organisation ainsi que le mode de fonctionnement du LARMAUR, futur département Mécanique et Verres. Ce poster est une synthèse de la politique qualité mise en place il y a deux ans, les objectifs attendus et les actions qualité réalisées sont décrits pour ce département de recherche qui est intimement lié à une filière une filière d’enseignement : Mécanique et Sciences pour l’Ingénieur de l’Université de Rennes1. Le département mécanique et verres est toujours dans une dynamique de travail sur la qualité, avec comme évènement marquant cette année les premiers audits internes de la qualité en recherche et en enseignement via des projets tuteurés de la Licence pro animateur qualité de l’IUT de Rennes. La démarche montre déjà très largement le bien fondé au quotidien de la mise en place des bonnes pratiques au sein d’une unité de recherche, et la réussite se mesure dans le temps par l’adhésion de la quasi-totalité du personnel du département à ce projet. 1Assistante Ingénieur en Instrumentation Scientifique et Techniques expérimentalesResponsable Qualité département Mécanique et [email protected] des UniversitésResponsable du département Mécanique et [email protected] de Physique de Rennes IPR UMR 6251 CNRSUniversité de Rennes 1Campus de Beaulie

Plasticity at nanoindentation site in glass : a possible experimental benchmark for numerical modeling

We have recently developed a technique allowing for the 3 dimensional probing, with a nanometer scale resolution, of small volumes affected by plastic events at Nano indentation sites. This method is sensitive to the structural changes in the glassy network (number of SiO4 units per ring, Si-O-Si inter-tetrahedral angle, connectivity loss) resulting from the densification. The plastic zone due to structural modifications has an enhanced reaction rate which, if coupled with precise atomic force microscopy measurements (AFM), may be used for probing and rebuilt the densified volume beneath nano indentation or nano scratch imprints made on a glass surface. Instrumented nano indentations and scratches (250 µN to 10 mN range) were made on various glass compositions. The effect of the applied load on the size and the shape of the plastic zone size is reported and compared to numerical simulations

Localized Atomic Segregation in the Spalled Area of a Zr50Cu40Al10 BMG Induced by Laser-shock Experiment

Laser-shock experiments were performed on a ternary Zr50Cu40Al10bulk metallic glass. A spalling process was studied through post-mortem analyses conducted on a recovered sample and spall. Scanning electron microscopy magnification of fracture surfaces revealed the presence of a peculiar feature known as cup-cone. Cups are found on sample fracture surface while cones are observed on spall. Two distinct regions can be observed on cups and cones: a smooth viscous-like region in the center and a flat one with large vein-pattern in the periphery. Energy dispersive spectroscopy measurements conducted on these features emphasized atomic distribution discrepancies both on the sample and spall. We propose a mechanism for the initiation and the growth of these features but also a process for atomic segregation during spallation. Cup and cones would originate from cracks arising from shear bands formation (softened paths). These shear bands result from a quadrupolar-shaped atomic disorder engendered around an initiation site by shock wave propagation. This disorder turns into a shear band when tensile front reaches spallation plane. During the separation process, temperature gain induced by shock waves and shear bands generation decreases material viscosity leading to higher atomic mobility. Once in a liquid-like form, atomic clusters migrate and segregate due to inertial effects originating from particle velocity variation (interaction of release waves). As a result, a high rate of copper is found in sample cups and high zirconium concentration is found on spall cones

Investigating ramp wave propagation inside silica glass with laser experiments and molecular simulations

Under elastic shock compression silica glass exhibits a very specific behaviour. A shock propagating inside a material is usually seen as the propagation of a discontinuity. However in silica glass, shocks are unstable and lead to the propagation of a ramp wave where the shock front becomes gradually larger over time. Ramp waves were already reported in the literature, however their origin remain uncertain. This work presents an original study combining laser shock-induced experiments and molecular dynamics simulation aiming to improve the understanding of the mechanisms involved. Experimental ramp waves were directly observed using shadowgraphy technique allowing for an estimation of the head and tail velocities. Molecular dynamics simulations were carried out in order to reproduce ramp waves and to gain insight into the material properties. Ramp waves were observed for both elastic and plastic shockwaves. In the latter case, the plastic waves were preceded by an elastic ramp precursor. The sound speed, related to the material compressibility, was found to decrease with increasing pressure, as observed experimentally for quasi-static hydrostatic loading, thus providing an explanation for the instabilities that lead to the propagation of ramp waves

State-of-the-art laser adhesion test (LASAT)

This paper proposes a state-of-the-art laser adhesion test. It consists of testing material interfaces with laser-driven shock wave. Since the first demonstration in the 1980s by Vossen, many studies and developments have been done. This paper presents recent experiments and developments on the basic physics involved. Results show the ability of the technique to perform a quantitative adhesion test for a wide range of materials and configurations. Edge effect principle and ultra-short shock wave give perspectives for new applications for multi-layer combination of material. Fundamental principles are evidenced through experiments on bulk ductile materials before demonstrating their application to coated systems

Laser induced dynamic fracture of fused silica: Experiments and simulations

Fused silica samples were subjected to laser induced shock loading. Laser flux was varied in order to obtain different amounts and characteristics of damage in the samples. Three dimensional damage and fracture maps of two identical samples impacted by high and low laser flux values were obtained using both optical microscopy and X-ray computed micro-tomography. Three prevalent fracture and damage patterns were identified. Peridynamic approach was used to simulate the laser impact conditions on the samples in order to explain the causes of the observed fracture and damage morphologies. A proprietary shock physics code, ESTHER, was used to calculate the transient kinetic energy imparted to the samples based on the experimental laser flux values. The kinetic energy values were then integrated over time and provided target values to match for the peridynamic impact conditions. The main fracture patterns were captured by peridynamic simulations with reasonable quantitative accuracy. Explanations for initiation and propagation of each of the fracture patterns were presented based on the peridynamic dynamic fracture simulations. Limitations of the computational approach and recommendations for future work is provided

Gas investigation for laser drilling

Version éditeur : http://jla.aip.org/resource/1/jlapen/v19/i3/p165_s1?isAuthorized=noThis article deals with the gas effect on percussion laser drilling in ms pulse duration range. On the one hand, the flow of assistance gas jet is investigated with and without a target using a strioscopy setup and Pitot’s tube. By this way, the position of shock waves in the supersonic jet and near the target surface is revealed. From this characterization, the distance between exit nozzle and target can be optimized to induce higher pressure on surface and protect optics from liquid ejection. On the other hand, metal liquid and vapor jets from irradiated target are observed with a high-speed camera (100 000 Img/sec). Without assistance gas, a surprising result on the video is a shock wave inside the metal vapor jet like a supersonic flow. The assistance gas limits the propagation of the vapor and facilitates the deposition of metallic liquid around the front surface holes

Pressure sensitivity of flow in metallic glasses: Indentation and reverse analysis

International audienc