DEVELOPMENT OF NEW MODE-SUPERPOSITION TECHNIQUE FOR TRUNCATING LOWER-FREQUENCY AND OR HIGHER-FREQUENCY MODES - APPLICATION OF EIGENMODE SENSITIVITY ANALYSIS FOR SYSTEMS WITH REPEATED EIGENVALUES

In this paper, the development of a modal sensitivity analysis method is described for a system with repeated eigenvalues. It is shown that the new algorithm proposed by the authors has much better computationa l accuracy than the method proposed by S. H. Chen and H. H. Pan, and t his method is simpler in terms of calculations than Ojalvo's and Daile y's methods, which was presented recently. The new method can also be extended to a coupled acoustic-structural system with repeated eigenva lues, and thus can be applied to vibration-noise reduction problems.