A branch mode method in dynamic substructuring

Let Omega be a bounded domain of R(3) made of I secondary subdomains Omega(i) connected to a master subdomain Omega(o) through the interfaces Sigma(i). The Helmholtz equation set in Omega is solved using a branch mode substructuring method in which the secondary subdomains are depicted by a set of eigenmodes. If these eigenmodes are computed after introducing the Laplace-Beltrami operator at the interfaces, it is shown that the approximation of the normal fluxes belongs to H-0(1) (Sigma(i)) in place of H-00(1/2) (Sigma(i)) as it is commonly the case.