An Optimal Design Method Regarding Large-scale Structure Using Reduced Model by Frequency Response Function. Development of a Method for Vibration Reduction by Additional Stiffness.

This paper presents an optimal design method regarding large scale structure subject to frequency response. It is difficult to directly apply an optimal design method to a large scale structure, because this model includes more than I million degrees of freedom. First, the dynamic mutual mean compliance is used as the measure of the acceleration at the observation grid and a sensitivity of the dynamic mutual mean compliance with respect to a scalar spring constant is formulated. A selection method of practical evaluation parts from a whole structure based on the measure of sensivities is proposed. Second, a new reduction method based on frequency response functions is presented. Third, an optimization problem, where the square of acceleration and additional spring constants are regarding as an objective function and design variables, respectively, is formulated. Finally, we demonstrate the effectiveness of the proposed method through the simple model.