NUMERICAL MODAL-ANALYSIS OF STRUCTURES BASED ON A REVISED SUBSTRUCTURE SYNTHESIS APPROACH

The classical substructuring approach to the problem of modal analysis of structures suffers from a number of drawbacks which can sometimes lead the analyst to prefer other, often more cumbersome, techniques. A modified Rayleigh-Ritz based approach is presented which circumvents most of the drawbacks and improves the precision of the method while also enhancing its applicability to complex structures. The scheme is also particularly well suited to symbolic implementation, in view of its systematic, problem-independent formulation. The theoretical results are validated by case studies chosen to highlight various features of the approach, viz., a beam structure, a hinged simple square plate, a hinged plate structure of fairly complicated shape, and a rectangular plate with two cutouts.