Consideration of Interface Damping in Dynamic Substructuring

Abstract

Dynamic substructuring offers the possibility to simulate assembled systems efficiently. The coupling of the substructures can be established either by Component Mode Synthesis (CMS), or Frequency Response Functions (FRF) can be used to couple the substructures by Frequency Based Substructuring (FBS). In real systems, coupling is done by joints which can influence the dynamics of the assembled system significantly due to local damping and nonlinearities caused by friction. In this contribution the coupling of two beam-like substructures, which are assembled by a bolted joint, is considered using both coupling methods. While the substructures are linear, the implementation of the nonlinear friction forces requires special attendance in the equations of motion. The Harmonic Balance Method is therefore used to efficiently compute FRFs. Using FBS, the coupling is established directly in the frequency domain. The method provides the possibility to replace the dynamics of individual substructures by measured FRFs of the uncoupled system and combining numerical and experimental models. Alternatively, Component-Mode-Synthesis is used.