ABSTRACT
This chapter discusses active control of response in discrete parameter adaptive structures for cases where there are excitations on the structure in addition to the actuator induced element deformations during the control. Although it is possible to control the response of a structural system by altering some of its parameters, in adaptive structures this is done by inserting deformations. The inserted deformations are the control variables. The energy imparted from excitations to a structure during the control plays a very important role in the control of adaptive structures. In non-autonomous systems when the excitations are of unknown and transient type, as in seismic excitations, one may be better off if one looks for non-optimal but admissible solutions. The actuator placement problem in the feedback control of non-autonomous systems depends not only on the control objectives but also on the nature of excitations.
