A Multi-Input Modal Estimation Algorithm for Mini-Computers

This paper describes a modal parameter estimation algorithm that uses frequency response functions relative to several exciter locations in a simultaneous manner. Phase information between the exciter locations is used to separate close or multiple roots, and consistent estimates are given for modal parameters and eigenvectors. An experimental investigation of a structure with repeated roots is described. In the single exciter location case, this method reduces to the least squares complex exponential technique.