Vibration confinement in flexible structures by distributed feedback

Abstract A method of confining the vibrations in parts of a flexible structure is proposed. The confinement is achieved by applying appropriate distributed feedback forces. The method of vibration confinement consists of converting the original mode shapes of continuous systems to exponentially decaying functions. It has been shown that the strategy of selecting the feedback forces, which lead to the vibration confinement, is dual to that of pole placement in the time domain control design. The method is applied to various one- and two-dimensional structures such as a string, a simply supported beam and a membrane. Simulations show that vibrations due to an impulse can be confined in a small region close to the location of the impulse. Finite element solution for the beam example is also obtained and compared to the analytical solution. It is anticipated that the proposed strategy may be a feasible method for eliminating unwanted vibrations from certain parts of a flexible structure more than others.