Thursday, 15 October 2020

Speaker: Prof. Jérémy Bleyer

Laboratoire Navier, École des Ponts ParisTech.

Multiphase continua for fiber-reinforced materials

Abstract

Fiber-reinforced materials exhibit interesting size effects due to the material contrast between fiber and matrix materials and the slenderness of the fibers. Homogenization theory cannot account for such effects when considering standard Cauchy continua. Multiphase continuum models are a class of generalized continua which consist of different media (fiber and matrix phases) possessing their own kinematics and in interaction with each other. An interaction energy depending on the difference of both phases displacements is at the origin of a size effect. Moreover, different boundary conditions can be prescribed at the same point for each phase, enabling to simulate, at the macroscopic level, matrix cracks bridged by intact fibers. We will describe a homogenization procedure for deriving the generalized material parameters in the elastic setting. This procedure will be then validated by comparing against finite-element computations on the heterogeneous structure. Finally, by considering a damage model for the matrix and the interface, we will show that regular microcracking can be obtained using this generalized continuum model.


Biography

Jeremy Bleyer graduated from Ecole Polytechnique and Ecole des Ponts ParisTech in 2011 and obtained his PhD from Université Paris-Est in 2015. After a one-year postdoc at EPFL, he is now a permanent researcher and associate professor at Ecole des Ponts ParisTech. He is a part-time professor at Ecole Polytechnique since 2020. His research topics focus on limit analysis theory, multi-scale techniques for heterogeneous materials and structures, phase-field approaches for brittle fracture with applications to civil engineering

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