Modal Substructuring (CMS) and Modal Substructure Modification

Suite of tools that perform modal substructuring and structural dynamic modification

Description

This submission contains an implementation of the modal substructuring approach described in Chapter 9 of Ginsberg, “Mechanical and Structural Vibrations,” Wiley, 2001. The well known Craig-Bampton component mode synthesis method is a special case of the approach implemented here. The routine ‘ritzscomb’ can be used to predict the mode shapes, natural frequencies and damping ratios of an assembly of substructures from the modes of the subcomponents and the constraints that are to be enforced. For simpler problems where one wishes to add or remove rigid springs or masses from a structure, the routine ‘ritzsmod’ can be used.

The methods implemented here were recently used in the following publication, where the “modal constraint” method, implemented in ‘mkmodalconstr’ was described in detail.

M. S. Allen, R. L. Mayes, and E. J. Bergman, "Experimental Modal Substructuring to Couple and Uncouple Substructures with Flexible Fixtures and Multi-point Connections," Journal of Sound and Vibration, 2010, doi:10.1016/j.jsv.2010.06.007

• MATLAB release: MATLAB 7.6 (R2008a)