Damping of coupled bending-torsion beam vibrations by spatially filtered warping position feedback

摘要

Damping of coupled bending-torsion beamvibrations is realized by local actuators, operating axially on an end cross-section of a fully three-dimensional structure by a collective positive position feedback control with a spatial filter that specifically targets the out-of-plane warping component of the coupled response. To reduce the computational effort, a beam element model is introduced, in which a single control bimoment is supplemented by a fictitious stiffness that accounts for the inability of the local actuators to fully restrain warping. This fictitious stiffness is conveniently calibrated by frequency matching in the limit of infinite control gain and it enables accurate estimation of both complex roots and the stability limit from beam element analysis. It is demonstrated by a numerical example that substantial modal damping is attained by positive position feedback of the torsional warping component from the fully coupled response. (C) 2020 Elsevier Ltd. All rights reserved.