Model Reduction and Model Expansion and Their Applications Part 1 - Theory

Model reduction and model expansion play an important part in many aspects of structural dynamic modeling techniques. These include reduced models for structural response studies, correlation of analytical and experimental models, expansion of measured mode shapes for structural dynamic modification and system models, and expansion for analytical model improvement studies using modal vectors. A mapping is needed between the analytical and experimental models typically used in these studies that is provided by the model reduction and model expansion processes. Contributions to this important area made by John O’Callahan are presented in this paper. This paper is broken down into Part 1 covering the theoretical aspects and Part 2 which addresses some of the applications of this material.