Optimal frequency response shaping by appendant structures

Two frequency response optimization methods for vibrating systems are developed by appending absorbers to the original structure. The methods are suitable for discrete models with a large number of degrees of freedom and are applied to obtain optimal broadband response. Reanalysis and modal techniques are used in the structural dynamic analysis phase of the design algorithm and optimization is carried out by a feasible directions approach. The optimal design algorithm is illustrated by several numerical examples for a 39 DOF helicopter model with discrete conventional absorbers and beam absorbers.