Optimal design of actively controlled adjacent structures for balancing the mutually conflicting objectives in design preference aspects

A preference-based optimal design approach for the actively controlled adjacent structures is proposed in this study. For the vibration control of connected adjacent structures subject to earthquake excitations, there exist many objective functions that are in conflicts with each other. It involves suppression of dynamic responses of the two structures and simultaneous minimization of control efforts such as control force, power and energy. Conventional optimal design technique has some difficulties in designing well-balanced control system between multiple objectives of performance and cost so as to exhibit the best performance on reducing incompatible responses of the coupled system with minimum control efforts. In the proposed method, the concept of degree of desirability and the preference function are introduced. By using the designers' preference, each design objective is aggregated and multi-objective optimization problem is formulated as finding the best compromising solution between structural control performance and control requirements. It is demonstrated in numerical example that the proposed approach is able to successfully mitigate the seismic impacts on both buildings by effectively utilizing and balancing the required control resources. As a result, the proposed system shows superior control performance to the conventionally designed control system in spite of using smaller control force, power and energy.