J. Phys. IV France 08 (1998) Pr8-197-Pr8-205
Computation of coarse grain structures using a homogeneous equivalent mediumS. Kruch1 and S. Forest2
1 ONERA, DMSE/LCME, BP. 72, 92322 Châtillon cedex, France
2 École des Mines de Paris, Centre des Matériaux, URA 866 du CNRS, BP. 87, 91003 Evry, France
This paper deals with the improvement of concentration relations when some basic hypothesis of homogenization techniques are no longer valid inducing important errors in the deduced local fields. In the first part of this work we propose a new formalism of the standard concentration rules developed in the homogenization of periodic media framework. In a second part, we insist on the fact that a homogeneous equivalent medium replacing a coarse grain material is in fact expected to be a generalized continuum. Additional stiffnesses must be attributed to the unit cell and special non-homogeneous boundary conditions and their periodic counterparts are proposed. The resulting HEM turns out to be a Cosserat continuum.
© EDP Sciences 1998