Search results for "matériaux"

Mechanical and acoustical behavior of sugarcane and flax fibres reinforced biocomposite

2017

For reasons of comfort, modern constructions require acoustic and thermal insulating materials, offering good mechanical performances. In this context, the valorization of plant fibres from the agro-food industry presents economic and environmental benefits. Thus, the aim of the present study is to develop a multifunctional sugarcane fibres reinforced epoxy porous composite combining good acoustic and mechanical properties.The study of the bagasse fibres geometry has shown that fibres’ length and diameter distribution can be fitted by lognormal laws. Composites manufactured by thermocompression process with an epoxy matrix were characterized using an experimental design whose parameters wer…

Thermal and hydrothermal ageing of bio-based composite/metal hybrid materials. Application to the development of ultra-light and durable street furni…

2021

In the perspectives of the future city, the progressive use of autonomous vehicles seems to become unavoidable. The preparation of an adequate framework for the deployment of this future mobility represents an important issue. This requires revisiting the urban infrastructures of cities from the choice of material to the design, and to propose solutions based on mobile street furniture. Faced with this challenge, hybrid materials such fibre metal laminates (FML) present interesting characteristics. FML made of plant fibre composites are of particular interest to minimize their environmental impact. Thus, the objective of this thesis is to design and manufacture plant-fibre metal laminates a…

Digitization and characterization of local reflectance of complex surfaces for visual inspection

2022

Mastering the visual perception of the surfaces of manufactured products is a central issue for industry. However, in industry, the quality of surfaces is often assessed by human inspectors. Only a few specific cases use an instrumental or photometric approach. Among the photometric approaches, one of them is experiencing significant growth: Reflectance Transformation Imaging (RTI). The RTI makes it possible to obtain a reduced and simplified estimate of the Bidirectional Reflectance Distribution Function (BRDF) and an estimate of the geometry of the surface. However, this technique has limitations in terms of data acquisition and processing. The objective is therefore to correct some of th…

Efficient growth of sub-micrometric MOF crystals inside the channels of AAO membranes

2013

International audience; A dynamic step-by-step methodology has been implemented to grow the HKUST-1 porous coordination polymer inside commercial anodic aluminium oxide membranes. Efficient crystal growth is achieved from the membrane inner walls and over the whole membrane thickness when copper acetate colloidal suspensions and benzene tricarboxylic acid solutions are forced to flow through the membrane. Sorption properties of the HKUST-1 embedded in membranes show selectivity for CO2 over CO, CH4, O2 and N2 similar to the bulk material.

Les matériaux de construction des églises de l’Yonne

2010

Au-delà de leurs caractéristiques architecturales, signatures de leurs bâtisseurs, les églises de l’Yonne portent aussi la marque de leur sous-sol, les intégrant ainsi et bien souvent dans le paysage. Cette constatation avait d’ailleurs été faite par Maximilien Quantin dans un remarquable article titré « Influence de la nature du sol sur les monuments religieux dans le département de l’Yonne » (BSSY, 1847). C’est, en effet, un véritable parcours de géologie régionale que l’on peut faire à travers ces églises qui portent en elles la diversité du sous-sol icaunais (granite, calcaire, argiles…).

Elaboration de matériaux à gradient de propriétés fonctionnelles pour les composants face au plasma des machines de fusion thermonucléaires

2014

The objective of this study was to develop a Functionally Graded Material (FGM) W / Cu to replace the compliance layer (Cu-OFHC) in the plasma facing components of thermonuclear fusion reactor like ITER. The peculiarity of this work is to elaborate these materials without exceeding the melting temperature of copper in order to control its microstructure. The co-sintering is the most attractive solution to achieve this goal.The first phase of this study has been to decrease the sintering temperature of the tungsten to achieve this co-sintering. The elaboration of a Functionally Graded Materials being delicate, thermo-mechanical calculations were performed in order to determine the number and…

Le tuffeau, un matériau apprécié dans la construction

2018

A physical-based constitutive model for surface integrity prediction in machining of OFHC copper

2017

International audience; Due to the rising interest in predicting machined surface integrity and sustainability, various models for metal cutting simulation have been developed. However, their accuracy depends deeply on the physical description of the machining process. This study aims to develop an orthogonal cutting model for surface integrity prediction, which includes a physical-based constitutive model of Oxygen Free High Conductivity (OFHC) copper. This constitutive model incorporates the effects of the state of stress and microstructure on the work material behavior, as well as a dislocation density-based model for surface integrity prediction. The coefficients of the constitutive mod…

Influence of cutting process mechanics on surface integrity and electrochemical behavior of OFHC copper

2014

The authors gratefully acknowledge the support received from IC ARTS and CEA Valduc; International audience; Superfinishing machining has a particular impact on cutting mechanics, surface integrity and local electrochemical behavior. In fact, material removal during this process induces geometrical, mechanical and micro-structural modifications in the machined surface and sub-surface. However, a conventional 3D cutting process is still complex to study in terms of analytical/numerical modeling and experimental process monitoring. So, researchers are wondering if a less intricate configuration such as orthogonal cutting would be able to provide information about surface integrity as close as…

Orthogonal cutting simulation of OFHC copper using a new constitutive model considering the state of stress and the microstructure effects

2016

International audience; This work aims to develop an orthogonal cutting model for surface integrity prediction, which incorporates a new constitutive model of Oxygen Free High Conductivity (OFHC) copper. It accounts for the effects of the state of stress on the flow stress evolution up to fracture. Moreover, since surface integrity parameters are sensitive to the microstructure of the work material, this constitutive model highlights also the recrystallization effects on the flow stress. Orthogonal cutting model is validated using experimental designed cutting tests. More accurate predictions were obtained using this new constitutive model comparing to the classical Johnson-Cook model.