Applications of Structural Dynamics Modification

The use of Structural Dynamics Modification (SDM) for determining changes in the dynamic characteristics of mechanical structures due to changes in their mass, stiffness, or damping properties, is presented. SDM requires as input the modal properties of the unmodified structure, which can be obtained either from a modal test or from finite element analysis. Structural modifications are then modeled as the addition (or removal) of mass, stiffness, or damping to the structure, and the resulting modal properties of the modified structure are determined. This same procedure can also be used to model the connection of two or more substructures, or the attachment of “tuned” vibration absorbers to a structure, and it predicts the new dynamic properties of the modified structure or coupled substructures.