抄録
A rational reduction method using modal analysis is developed in order to analyze accurately a large-scale nonlinear system. Nodes without nonlinear excitation are transformed into the modal coordinates, and the modes with significant effect on computation accuracy of the vibration analysis are extracted. On the other hands, the remaining modes with small effect are appropriately approximated and are eliminated. The very accurate low-dimensional model is constructed by these procedures. The effectiveness of this method is verified from the computational results.