Finite element simulation of smart structures for active vibration and acoustic control. The design process of engineering smart structures using piezoelectric patches as distributed sensors and actuators requires a virtual overall model, which includes the main functional parts. In the paper a suitable software tool based on the FEM is presented to simulate coupled electro-mechanical-acoustical problems regarding interior noise problems. The modal truncation technique is used to design a LQ-controller as well as to study the time-depending behaviour of a clamed smart plate.