Developed in collaboration with Airbus Defence and Space, this thesis aims to investigate and develop a specialized methodology for representing localized frequency-dependent damping properties within condensed models. While modern satellites increasingly rely on advanced damping devices to reduce vibrations during launch, their frequency and strain-dependent properties present several modelling challenges. In Nastran these non-linear properties, modelled with PBUSHT entries, are lost during the Craig-Bampton condensation process. As these properties significantly impact the dynamic response of the damped components, it is desirable to have an applicable representation available in the condensed model as well. These are required, for example, for the Coupled Loads Analysis (CLA) by the Launch Authorities.