Active control of flexural power flow in elastic thin beams

Active control of flexural power flow in infinite, semi-infinite and finite beams by point force inputs has been analytically and experimentally studied. The systems were analyzed by assuming wave solution and then applying various terminating boundary conditions. Optimal control solutions were then obtained using a quadratic Wiener solution. The influence of system parameters such as discontinuity impedance and effects such as near fields, number and location of control actuators and error sensors is investigated and discussed. The mechanisms by which control is achieved are considered. It is demonstrated that the boundary conditions and the system configuration strongly influence the choice of optimal controller format. The experimental work is compared with the theoretical developments and found to be in good agreement. Control was achieved by a LMS Filtered-x algorithm implemented in assembler language on a TMS32020 digital signal processing chip. In general it is demonstrated that the flexural power flow in the beam types considered can be attenuated with a low number of active actuators.