9703020 Abdullah The dynamic responses of structures can produce situations that can range from uncomfortable to unsafe for the building occupants. In recent years, control theories and technologies have been used to reduce the dynamic responses of tall civil structures. Most optimal control algorithms involve full state feedback control. This type of control requires good estimates of the velocity and displacement throughout the structure. However, there are several important advantages of output feedback control: it requires less computational effort and has the robustness of a passive system. In the research conducted under this CAREER award, control algorithms will be formulated for the optimization of feedback gains and controller placement for flexible continuous and discrete structures, such as tall buildings. Tall buildings are of particular interest because the control devices must be placed at floor level. The fundamental basis for these algorithms is the calculation of the gradients of the performance function with respect to the gain and placement matrices. For the optimal placement of controllers at discrete locations in flexible continuous structures, a mixed-integer method will be used to optimize the placement and gains simultaneously. The effectiveness of the algorithm will be demonstrated for stochastic wind loads in the frequency domain and for deterministic earthquake loads in the time domain. The educational component of this CAREER award will involve creating Web-based modules for use in graduate and undergraduate courses to demonstrate the concepts of structural dynamics and civil engineering control devices. ***
