MODAL CONTROL OF MULTISTORY STRUCTURES

The design of active control systems for civil engineering structures is considered using modal control concepts. The theory of modal control is briefly presented with respect to the control of linear structures where the control objective is to direct changes of its specific dynamic modes and stiffness. The numerical example makes clear that in the design of modal control, a great deal of freedom exists in terms of eigenvalue assignments and control policy decision. The task of making appropriate choices must be guided by physical constraints, economic and engineering feasibilities, and experience and good judgment on the part of the designer. This freedom of choice gives rise to suboptimal control in general. On the other hand, it can have a positive effect on control design since practical considerations can be easily implemented, which in turn makes it possible to determine a ″feasible control″ in short order.