Computational Homogenization of Architectured Materials

Architectured materials involve geometrically engineered distributions of microstructural phases at a scale comparable to the scale of the component, thus calling for new models in order to determine the effective properties of materials. The present chapter aims at providing such models, in the case of mechanical properties. As a matter of fact, one engineering challenge is to predict the effective properties of such materials; computational homogenization using finite element analysis is a powerful tool to do so. Homogenized behavior of architectured materials can thus be used in large structural computations, hence enabling the dissemination of architectured materials in the industry. Furthermore, computational homogenization is the basis for computational topology optimization which will give rise to the next generation of architectured materials. This chapter covers the computational homogenization of periodic architectured materials in elasticity and plasticity, as well as the homogenization and representativity of random architectured materials

Mechanical properties and non-homogeneous deformation of open-cell nickel foams: application of the mechanics of cellular solids and of porous materials

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Experimental Evidence of Photon Acceleration of Ultrashort Laser Pulses in relativistic Ionization Fronts

International audienceThe frequency up-shifts of ultrashort laser pulses (65 fs) propagating in opposite directions (20° and 160°) with respect to a relativistic ionization front (interface gas plasma) are measured for the first time. Up-shifts of the order of 25 nm are observed. A very good agreement is found with a two-dimensional ray-tracing theory