THE EFFECTS OF TIME-DELAYED ACTIVE DISPLACEMENT CONTROL ON DAMPED STRUCTURES

In this paper, we discuss the asymptotic stability of a class of damped structures, using active displacement feedback control in which there is a time delay. The asymptotic conditions of stability are formulated and compared with known conditions. Without the control, the inherent damping of the structure has a stabilizing effect, whereas the introduction of an active displacement control with time delay can have a destabilizing effect. With this in mind, an analysis of the effectiveness of using displacement control under these conditions is studied. Specific numerical results are given for a structurally damped beam when the dis placement control is applied with a time delay.