The work presents an automatic process for the selection of modes of substructures with the purpose of buiding the superset of a residual flexibility model. This superset in used in the modal synthesis method for the experimental analysis of large structures. The qualitative indication of modes to be eliminated in a substructure plays an important role in the precision of the synthesis process. Actual mode elimination techniques are based on arbitrary user decisions which could lead to the extinction of modes which would have an important contribution to the synthesis of the complete structure. The technique is applied here for systems without damping. Such a technique relies on a relative weighting of the modes of the substructures, based on Euclidian norm calculations.204656665Arruda, J.R.F., Santos, J.M.C., Experimental Estimation of Mechanical Joint Parameters Using Frequency Response Functions and Modal Parameters (1993) 11 th. Int. Conf. on Modal Analysis IMAC, pp. 1502-1507Craig R.R., Jr., Methods of Component Mode Synthesis (1977) Shock and Vib. Dig., 9 (11), pp. 3-10Craig R.R., Jr., Chang, C.J., On the Use of Attachment Modes in SubstructureCoupling for Dynamic Analysis (1977) AIAA/ASME 18th Struct., B, pp. 89-99Craig R.R., Jr., A Review of Time-Domain and Frequency-Domain Component Mode Synthesis Methods (1987) J. of Modal Analysis, pp. 59-72Duarte, M.A.V., (1994) Ajuste de Modelos de Dinâmicos de Estruturas Com Não Linearidades Concentradas, , Doctoral thesis, Unicamp - CampinasEwins, D.J., (1994) Modal Testing: Theory and Practice, , John Wiley & Sons, New YorkHintz, R.M., Analytical Methods in Component Modal Synthesis (1975) AIAA J., 13 (8), pp. 1007-1016Hurty, W.C., Dynamic Analysis of Structural Systems Using Component Modes (1965) AIAA J., 3 (4), pp. 678-685Hurty, W.C., Collins, J.D., Hart, G.C., Dynamic Analysis of Large Structures by Modal Synthesis Techniques (1971) J. Computers & Struct., 1 (4), pp. 535-563Kreyszis, E., (1993) Advanced Engineering Mathematics, , John Wiley & Sons, Inc., 7a. edKurka, P.R.G., Bazán, F.S.V., Regularization Techniques in the Time Domain Modal Parameter Identification (1992) 17th International Seminar on Modal Analysis, pp. 221-225. , Catholic University of Leuven, BelgiumMatrix Eigensystem Routines - EISPACK Guide (1976) Lecture Notes in Computer Science, 6. , Springer-Verlag, 2nd EditionMacneal, R.H., A Hibrid Method of Component Mode Synthesis (1971) Computers and Struct., 1 (4), pp. 581-601Rubin, S., Improved Component-Mode Representation for Structural Dynamic Analysis (1975) AIAA J., 13 (8), pp. 995-1006Santos, J.M.C., (1993) Ajuste de Modelos de Estruturas Acopladas por Juntas Mecânicas Usando Funções de Resposta em Frequência e Síntese Modal de Componentes, , Doctoral thesis, Unicamp - Campina
