Effects of gain and delay time of control devices to structural study

The effects of several combinations of gain and delay time on the control of such flexible structures as tall buildings and long bridges are studied. Investigations of active structural control, active damping of large structures in winds, antiearthquake application of pulse generators, active feedback control, modal synthesis, and modal control are reviewed. To reduce undesirable effects of disturbances, the feedforward control system, the feedback control system, or a combination of the two may be used. Ways to minimize the effects of the disturbance force are examined. An example is provided of a single-degree-of-freedom structural system subjected to an artificially generated earthquake. It is found that the larger the gain and the smaller the delay time, the more effective the control system will be.