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

In this paper, we discuss the asymptotic stability of a class of dampe d structures, using active displacement feedback control in which ther e is a time delay. The asymptotic conditions of stability are formulat ed and compared with known conditions. Without the control, the inhere nt damping of the structure has a stabilizing effect, whereas the intr oduction of an active displacement control with time delay can have a destabilizing effect. With this in mind, an analysis of the effectiven ess of using displacement control under these conditions is studied. S pecific numerical results are given for a structurally damped beam whe n the dis placement control is applied with a time delay.