A GENERALIZED MULTIPLE-INPUT, MULTIPLE-OUTPUT MODAL PARAMETER-ESTIMATION ALGORITHM

A new method for experimental determination of the modal parameters of a structure is presented. The method allows for multiple-input forces to be applied simultaneously and for an arbitrary number of acceleration response measurements to be employed. These data are used to form the equations of motion for a damped linear elastic structure. The modal parameters are then obtained through an eigenvalue technique. In conjunction with the development of the equations, an extensive computer simulation study was performed. The results of the study show a marked improvement in the mode shape identification for closely-spaced modes as the number of applied forces is increased. Also demonstrated is the influence of noise on the method's ability to identify accurate modal parameters. Here again, an increase in the number of exciters leads to a significant improvement in the identified parameters. Refs.