Multiscale expansion and numerical approximation for surface defects V. Bonnaillie-Noël, D. Brancherie, M. Dambrine, F. Hérau, S. Tordeux and G. Vial ESAIM: Proc., 33 (2011) 22-35 Published online: 22 December 2011 DOI: 10.1051/proc/201133003