A REFINED MODAL COUPLING TECHNIQUE FOR INCLUDING RESIDUAL EFFECTS OF OUT-OF-RANGE MODES

摘要

This work presents a refined approach for the dynamic analysis of coupled structures using experimentally-derived modal data for one or more of the components. The component models are derived by assuming free-interface support conditions, this being a requisite for the methods using both experimental and theoretical input data into the coupling process. The equation of motion for the overall structure is constructed by invoking the force equilibrium between two components, which in turn are connected through an intermediate elastic system. This auxiliary system has specific stiffness properties which are derived from the residual flexibility properties associated with the higher unmeasured or neglected modes for each component. In addition to numerical case studies to demonstrate the approach, an experimental case is presented, based on a structure formed of two parts. For each of these, experimentally-derived models are established and constitute the input data for the coupling process. The predicted dynamic characteristics are then compared with the measured ones, both with and without the residual correction being included, clearly demonstrating the significance and facility of the refinement.