The effective behavior of elastic bodies containing microcracks or microholes localized on a surface

We propose a two-scale method to find the effective behavior of a three-dimensional linear elastic medium containing a series of microcracks or micro- holes located on a surface. The obtained effective behavior is that of a homogeneous body with, in place of the actual microdefects, a surface across which the displace- ments and the stresses suffer jump discontinuities. The transmission conditions are in general of Ventcel's type. The coefficients entering in these jump conditions are obtained by solving six elastic problems posed on an infinite representative cell. The theoretical analysis is illustrated by a few examples.