A family of substructure decoupling techniques based on a dual assembly approach

In recent years, the structural dynamic community showed a renewed interest in dynamic substructuring (i.e. component coupling) techniques, especially in an experimental context. In this paper the reverse problem is addressed: the decoupling (or identification) of a substructure from an assembled system. This problem arises when substructures cannot be measured separately but only when coupled to neighboring substructures, a situation regularly encountered in practice. In this work we present a so-called dual approach to substructure (dis)assembly. In a transparent and straightforward manner, this dual framework allows imposing different equilibrium and compatibility conditions during decoupling in both the physical and modal space. Five substructure decoupling techniques will be derived and/or classified in a unified way by varying these conditions. Thereafter, the decoupling techniques will be applied to two case studies: the first is an academic example, the second a practical decoupling problem using measured data.