The study of rotative machines occupies an outstanding position in the context of machines and structures in view of the significant amount of typical phenomena in the operation of those equipments. The existence of a rotative component leaning by bearings and transmitting power and torque creates a family of problems that are found in the most several machines. Therefore, in the study of the dynamic behavior of those systems, it is necessary to be determined the interaction among all the components that affect in a significant way the dynamic behavior of the system. It is proposed, this way, a simplified mathematical model, through the method of finite elements, of the Rotor-Bearing-Coupling system, considering the support structure or foundation practically rigid, in way to allow the analysis of the transverse or flexional vibrations of the system. With the purpose of analyzing the influence of the model of the coupling in the dynamic behavior of the system, a simplified model was considered to represent it in the mechanical systems. Usually, the coupling is modeled as a rigid disk, or as part of the shafts connected axially, disregarding its flexibility and capacity of damping the vibrations, coming of the shaft offset or misalignment of the shafts. However, little information exists about the dynamic behavior of the stiffness coefficients and of damping of the couplings, as well as of the forces and moments generated due to the misalignment in the same ones, and that are acting on the shaft of the mechanical systems. For its time, the dynamic coefficients as the forces and moments of reaction are influenced by the rotation and for the type and degree of misaligment of the shafts. Copyright © 2002 Society of Automotive Engineers, Inc. Lee, C.W., A new modal testing in rotating (1990) International Conference of Modal Analysis, 17, 1, pp. 148-154. , Kissimmee, Florida: AnaisLee, C.W., A complex modal testing theory for rotating machinery (1991) Mechanical Systems and Signal Processing, 5 (2), pp. 119-137Lee, C.W., Joh, Y.D., Excitation methods and modal parameter identification in complex modal testing of rotating machinery (1993) Modal Analysis: The International Journal of Analytical and Experimental Modal Analysis, 8 (3), pp. 179-203. , JulLee, C.W., Joh, Y.D., Theory of excitation methods and estimation of frequency response functions in complex modal testing of rotating machinery (1993) Mechanical Systems and Signal Processing, 7 (1), pp. 57-74. , JanKessler, C.L., (1999) Complex Modal Analysis of Rotating Machinery, p. 108. , Cincinnati, Department of Mechanical, Industrial and Nuclear Engineering, Tese de DoutoradoLalanne, M., Ferraris, G., (1990) Rotordynamics: Prediction in Engineering, p. 196. , John Wiley and Sons: New YorkCavalca, K.L., Dedini, F.G., Experimental analysis of a tilting pad journal bearing influence in a vertical rotating system IFToMM 1998 - 5th Internetional Conference Om Rotor Dynamics, pp. 571-582. , Darmstadt - Alemanha, 7-10 SeptemberIdehara, S.J., Cavalca, K.L., (2000), Calibração experimental de modelo não linear de mancais hidrodinâmicos". Faculdade de Engenharia Mecânica - Unicamp - Trabalho de Iniciação Científica, Dezembro deCavalca, K.L., Cavalcante, P.F., Okabe, E.P., An experimental analysis of rotors on flexible structures IFToMM 2002 - 6th Internetional Conference on Rotor Dynamics, , UNSW - Sydney - Australia -30/09 a 3/10Krämer, E., (1993) Dynamics of Rotors and Foundations, p. 384. , London: Springer-VerlagNelson, H.D., McVaugh, J.M., Dynamics of Rotor-Bearing Systems Using Finite Elements (1976) ASME Journal of Engineering for Industry, 98, pp. 593-600Arruda, J.R.F., Duarte, M.A.V., Updating Rotor-Bearing Finite Element Models Using Experimental Frequency Response Functions (1993) RBCM-J. of the Braz. Soc. Mechanical Sciences, 15 (2), pp. 136-149. , 1993Nordmann, R., (1982) Modal Parameter Identification and Sensitivity Analysis in Rotating Machinery, pp. 95-102. , IFToMM, Roma: AnaisIrretier, H., Mathematical foundations of experimental modal analysis in Rotor Dynamics (1999) Mechanical Systems and Signal Processing, 13 (2), pp. 183-191Ewins, D.J., (1984) Modal Testing Theory and Practice, , RSP John Wiley, LetchworthEwins, D.J., Modal Analysis for rotating machinery (1998) IFToMM 5th International Conference on Rotor Dynamics, p. 13. , In: Darmstadt, SeptemberTapia, A.T., Cavalca, K.L., Dedini, F.G., (2001), pp. 44-53. , Efeito da Modelagem dos Acoplamentos Flexíveis nos Sistemas Mecânicos. XVI Congresso Brasileiro de Engenharia Mecânica (COBEM2001), Uberlandia-Brasil, NovembroTapia, A.T., Cavalca, K.L., Modeling effect of flexible and rigid couplings in Mechanical System IFToMM 2002 - 6th Internetional Conference Om Rotor Dynamics, , UNSW - Sydney - Australia -30/09 a 3/10