Nonbaseband residual flexibility method of component mode synthesis for proportionally damped systems

Several new component mode synthesis methods are presented for the dynamic analysis of proportionally damped systems in nonbaseband frequency regions of interest, The first method is based on the Craig-Bampton constraint modes approach (Craig, R. R., Jr., and Bampton, M. C. C., "Coupling of Substructures for Dynamic Analyses," AIAA Journal, Vol. 6, No. 7, 1968, pp. 1313-1319) but uses a modified dynamic transformation method that produces constraint modes at two frequencies, normally the upper and lower frequency limits of the region of interest. Then, a second method is presented that is similar to the first but uses a residual flexibility formulation. This second method Is ideally suited for use with test-derived data and becomes the bash for a new nonbaseband experimentally based method. The procedure for implementing the experimentally based method is then presented. Finally, an analytical simulation is conducted using error-free data to demonstrate the new methods on a system of two coupled beams.