Local modal reduction in explicit dynamics with domain decomposition. Part 2: specific interface treatment when modal subdomains are involved

During the last 2 years, a multidomain formalism for structural dynamics based on a multi-time-step algorithm and local linear modal reduction was proposed by Gravouil, Combescure, Herry & Faucher. In the first part of this paper, we extended modal reduction to subdomains undergoing finite rigid-body rotations. Here, we focus on the consequences of local modal projection (either linear or geometrically non-linear) on the treatment of interface problems between subdomains. In particular, we address the issues of the invertibility and efficiency of the solution process. We illustrate our propositions with specific interpretations of the examples presented in Part 1 and present an additional example to demonstrate the properties of special sets of modes