An optimal control algorithm using neural networks is proposed. The control
ler neural network is trained by a training rule developed to minimize cost
function. Both the linear structure and the nonlinear structure can be con
trolled by the proposed neurocontroller. A bilinear hysteretic model is use
d to simulate nonlinear structural behavior. Three main advantages of the n
eurocontroller can be summarized as follows. First, it can control a struct
ure with unknown dynamics. Second, it can easily be applied to nonlinear st
ructural control. Third, external disturbances can be considered in the opt
imal control. Examples show that structural vibration can be controlled suc
cessfully.