Dynamic analysis of large structures by modal synthesis techniques.

Abstract The past decade has seen the development of several techniques for the dynamic analysis of large structures that involve division into substructures or components. These techniques make use of component displacement modes to synthesize global systems of generalized coordinates and, for that reason, they have come to be known as modal synthesis or component mode techniques. This paper discusses some of the approaches used to develop structural dynamic characteristics from substructure dynamic characteristics. Several criteria that may be used to evaluate the merits of the various methods are discussed. Two methods classed as (1) fixed-attachment mode and (2) free-attachment mode methods are developed in detail. General flow charts are presented that can be used in preparing computer programs.