A HYBRID FORMULATION OF A COMPONENT MODE SYNTHESIS METHOD

Component mode synthesis is a substructuring technique frequently employed in structural dynamics. In this method, a given structure is subdivided into components or substructures, each of which is analyzed independently for natural frequencies and for mode shapes. The substructure mode shapes are then assembled to give displacement shapes or load patterns of the original structure. Here, we present first an analytical justification of the basic concept using spectral decompositions, then derive a variant substructuring approach where inter-substructure continuity is cnforced in a weak form. This leads to a hybrid formulation of the basic neth hod which is particularly suitable for assembling heterogeneous substructures and analyzing non-conforl~iing and inconlpatible finite element substructure inodels. For problems where both the basic and hybrid nicthods arc applicable, we show that the hybrid variant can be co~~lputationall y more advantageous.