Minimax design of parallel multi-mass dynamic vibration absorbers

This thesis discusses the design of multi-mass dynamic vibration absorbers in parallel configuration subject to uncertainties in the forcing frequency. A minimax parameter optimization approach is used to determine the optimum absorber mass parameters for different numbers of vibration absorbers without changing the total vibration absorber mass (constant mass ratio). Both main mass excitation and base excitation systems are examined. The effects of increasing the number of absorber masses are analyzed qualitatively through analysis of the system transfer function as well as quantitatively via numerical simulations. Increasing the number of absorber masses is shown to give improved robustness and overall vibration reduction in the main mass at the cost of increased motion of the absorber masses.