Search results for "Material Properties"

Transport de la variabilité dans les matériaux composites = Uncertainties propagation in composite materials

2009

National audience; Dans ce travail, une méthodologie de transport d'incertitudes à travers les différentes échelles d'observation des matériaux composites : (i) micro (fibres et matrice), (ii) méso (pli), (iii) macro (matériau stratifié) est proposée. L'objectif est d'intégrer à l'échelle macro (celle du calcul de structure) l'effet des incertitudes venant de l'échelle micro et celle des incertitudes introduites à chacune des échelles méso et macro. La démarche proposée s'appuie sur l'élaboration dès l'échelle micro de distributions statistiques bâties sur l'analyse morphologique et obtenues grâce à la génération de matériaux virtuels.

COMPUTATIONAL HOMOGENIZATION OF POLYCRYSTALLINE MATERIALS WITH PORES: A THREE-DIMENSIONAL GRAIN BOUNDARY FORMULATION

2012

In this study, the influence of porosity on the elastic effective properties of polycrystalline materials is investigated using a 3D grain boundary micro mechanical model. The volume fraction of pores, their size and distribution can be varied to better simulate the response of real porous materials. The formulation is built on a boundary integral representation of the elastic problem for the grains, which are modeled as 3D linearly elastic orthotropic domains with arbitrary spatial orientation. The artificial polycrystalline morphology is represented using 3D Voronoi Tessellations. The formulation is expressed in terms of intergranular fields, namely displacements and tractions that play …

FRP reinforcement for concrete structures: state-of-the-art review of application and design

2014

Fiber reinforced polymers (FRPs) are considered to be a promising alternative to steel reinforcement, especially in concrete structures subjected to an aggressive environment or to the effects of electromagnetic fields. Although attempts to develop effective reinforcement have been followed, the application of FRPs remains limited by the solution to simple structural problems that mainly appear due to the absence of design codes, significant variation in the material properties of FRP composites and limited knowledge gained by engineers as regards the application aspects of FRP composites and structural mechanics of concrete elements reinforced with FRPs. To fill the latter gap, the current…

Formulas for the thermodynamic properties of dense nitrogen.

1969

Effect of Boron Doping on the Wear Behavior of the Growth and Nucleation Surfaces of Micro- and Nanocrystalline Diamond Films

2016

B-doped diamond has become the ultimate material for applications in the field of microelectromechanical systems (MEMS), which require both highly wear resistant and electrically conductive diamond films and microstructures. Despite the extensive research of the tribological properties of undoped diamond, to date there is very limited knowledge of the wear properties of highly B-doped diamond. Therefore, in this work a comprehensive investigation of the wear behavior of highly B-doped diamond is presented. Reciprocating sliding tests are performed on micro- and nanocrystalline diamond (MCD, NCD) films with varying B-doping levels and thicknesses. We demonstrate a linear dependency of the we…