ACTIVE CONTROL OF BENDING AND TORSIONAL MODES IN TRUSS STRUCTURES

There is increased interest in active vibration control of flexible structures by using piezoceramics and piezopolymers as sensors and actuators. In this paper, the control of low frequency vibrations of structures such as cantilever beams, relatively complicated truss structures with and without end masses, is considered. Structural torsion and bending modes are simultaneously controlled. In all cases the damping factors obtained with active control are one to three orders of magnitude larger than that of the uncontrolled structure. The emphasis of this work is on experimental results for various structures and not on the implementation of different control algorithms. From the experimental results presented, it is concluded that discrete piezoelectric sensors and actuators combined with modern control algorithms offer an attractive method for increasing the damping ratio of vibrating structures with minimal increase of mass and minimal consumption of power. © 1993 Academic Press Limited.