On Nonlinear Dynamics And Control Of A Particular Portal Frame Foundation Model, Excited By A Non-ideal Motor

The nonlinear dynamic response and a nonlinear control method of a particular portal frame foundation for an unbalanced rotating machine with limited power (non-ideal motor) are examined. Numerical simulations are performed for a set of control parameters (depending on the voltage of the motor) related to the static and dynamic characteristics of the motor. The interaction of the structure with the excitation source may lead to the occurrence of interesting phenomena during the forward passage through the several resonance states of the systems. A mathematical model having two degrees of freedom simplifies the non-ideal system. The study of controlling steady-state vibrations of the non-ideal system is based on the saturation phenomenon due to internal resonance.440-441371378Sommerfeld, A., Beitrag zum Dynamischen Ausbau de Festigkeitslehre (1904) Physikalische Zeitschr, 4, pp. 631-636Kononenko, V.O., (1969) Vibrating Systems with a Limited Power Supply, , Iliffe Books, LondonNayfeh, A.H., Mook, D.T., (1979) Nonlinear Oscillations, , John Wiley, New YorkBalthazar, J.M., Mook, D.T.D.T., Brasil, R.M.L.R.F., Weber, H.I., Fenili, A., Belato, D., Felix, J.L.P., An overview on non-ideal vibrations (2003) Meccanica, , Accepted to publicationPai, P.F., Wen, B., Nasser, A.S., Schulz, M.J., Structural Vibration Control Using PZT Patches and Nonlinear Phenomena (1998) Journal of Sound and Vibration, 215 (49), pp. 273-296Queini, S.S., Nayfeh, A.H., Golnaraghi, M.F., A Theoretical and Experimental Implementation of a Control Method Based on Saturation (1996) Nonlinear Dynamics, 13, pp. 189-202Nayfeh, A.H., (2000) Nonlinear Interactions, , John Wiley, New YorkFelix, J.L.P., (2002) Nonlinear Dynamic and Control of a Portal Frame Structure, Excited by a Non-ideal Source, , Doctor Thesis, UNICAMP, Campinas, SP, Brasil, in Portugues

An Overview On Non-ideal Vibrations

We analyze the dynamical coupling between energy sources and structural response that must not be ignored in real engineering problems, since real motors have limited output power.386613621Sommerfeld, A., Beiträge zum dynamischen ausbau der festigkeitslehe (1902) Physikal Zeitschr, 3Kononenko, V.O., (1969) Vibrating Systems with a Limited Power Supply, , (in Russian: 1959), English translation, Illife BooksBleckman, I.I., Self-synchronization of certain vibratory devices (1953) Eng. Trans., 16Evan-Iwanowski, R.M., (1976) Resonance Oscillators in Mechanical Systems, , ElsevierDimentberg, M.F., (1988) Statistical Dynamics of Nonlinear and Time Varying Systems, , John Wiley and SonsDimentberg, M.F., McGovern, L., Norton, R.L., Chapdelaine, J., Harrison, R., Dynamics of an unbalanced shaft interacting with a limited power supply (1997) Nonlinear Dyn., 13, pp. 171-187Nayfeh, A.H., Mook, D.T., (1979) Nonlinear Oscillations, , John Wiley and SonsBalthazar, J.M., Mook, D.T., Weber, H.I., Fenili, A., Belato, D., De Mattos, M.C., Wieczorek, S., On vibrating systems with a limited power supply and their applications to engineering sciences 49th Brazilian Seminar of Mathematical Analysis, State University of Campinas, Campinas, SP, Brazil, Short Course, March 5-9, 1999, pp. 137-277. , in: Honig, C.S. (ed)Balthazar, J.M., Mook, D.T., Brazil, R.M.L.R.F., Weber, H.I., Fenili, A., Belato, D., Felix, J.L.P., Recent results on vibrating problems with limited power supply Sixth Conference on Dynamical Systems Theory and Applications, Lodz, Poland, December, 10-12, 2001, pp. 27-50. , in: Awrejcewicz, J., Brabski, J. and Nowakowski, J. (eds)Yamanaka, H., Murakami, S., Optimum designs of operating curves for rotating shaft systems with limited power supplier (1989) Current Topics in Structural Mechanics, PVP, 179, pp. 181-185. , in: Chung, H. (ed.)ASME NYBalthazar, J.M., Cheshankov, B.I., Rushev, D.T., Barbanti, L., Weber, H.I., Remarks on the passage through resonance of a vibrating system, with two degree of freedom (2001) J. Sound Vib., 239 (5), pp. 1075-1085Christ, H., Stationärer und Instatioärer Betrieb Eines Federnd Gelagerten, Unwuchtigen Motors (1966), Dissertation Universität KarlsruheWauer, J., Bürle, P., Dynamics of a flexible slider-crank mechanism driven by a non-ideal source of energy (1997) Nonlinear Dyn., 13, pp. 221-242Wauer, J., Suherman, S., Vibration suppression of rotating shafts passing through resonances by switching shaft stiffness (1997) J. Vib. Acoust., 120, pp. 170-180Suherman, S., Transient analysis and vibrating suppression of a cracked rotating shaft with a ideal and a non-ideal motor passing through a critical speed (1996), PhD Thesis, Virginia Polytechnic Institute and State UniversityIwatsubo, T., Kanki, H., Kawai, R., Vibration of asymmetric rotor through critical speed with limited power supply (1972) J. Mech. Eng. Sci., 14 (3), pp. 184-194Suzuki, S.H., Dynamic behavior of a beam subject to a force of time-dependent frequency (1978) J. Sound Vib., 57, pp. 59-64Suzuki, S.H., Dynamic behavior of a beam subject to a force of time-dependent frequency (continued) (1978) J. Sound Vib., 60 (3), pp. 417-422Balthazar, J.M., Rente, M.L., Mook, D.T., Weber, H.I., Some observations on numerical simulations of a non-ideal dynamical system (1997) Nonlinear Dynamics, Chaos, Control and Their Applications to Engineering Sciences, 1, pp. 97-104. , in: Balthazar, J.M., Mook, D.T. and Rosario, J.M. (eds)Balthazar, J.M., Mook, D.T., Weber, H.I., Mattos, M.C., Some remarks on the behaviour of non-ideal dynamical systems (1997) Nonlinear Dynamics, Chaos, Control and Their Applications to Engineering Sciences, 1, pp. 88-96. , in: Balthazar, J.M., Mook, D.T. and Rosario, J.M. (eds)De Mattos, M.C., Balthazar, J.M., Wieczork, S., Mook, D.T., An experimental study of vibrations of non-ideal systems Proceedings of DETC'97, ASME Design Engineering Technical Conference, September 14-17, Sacramento, California, USA, CD-ROM, 1997, p. 10De Mattos, M.C., Balthazar, J.M., On the dynamics of an armature controlled dc motor mounted on an elastically table Proceedings of 15th Brazilian Congress of Mechanical Engineering, November 22-16, Águas de Lindóia, São Paulo, Brazil, 1999, p. 10Brasil, R.M.F.L., Balthazar, J.M., Nonlinear oscillations of a portal frame structure excited by a non-ideal motor (2000) Control of Oscillations and Chaos, 2, pp. 275-278. , in: Chernousko, A.L. and Fradkov, A.I. (eds)Palacios, J.F., Balthazar, J.M., Brasil, R.M.L.R.F., On non-ideal dynamics of nonlinear portal frame analysis using averaging method Proceedings of the Ninth International Symposium on Dynamic Problems of Mechanics, Florianópolis, SC, Brazil, 5-9 March 2001, pp. 341-346. , in: Espindola, J.J., Lopes, E.O.M. and Bazan, F.S.V. (eds)Fenili, A., On slewing structure: Modeling and dynamical analysis (2000), PhD Thesis, State University of Campinas, SP, Brazil(in Portuguese)Fenili, A., Balthazar, J.M., Weber, H.I., Mook, D.T., Nonlinear analysis of the motion of a flexible, rotating, cantilever beam (2002), (submitted)Fenili, A., Balthazar, J.M., Weber, H.I., Mook, D.T., On the comparison between two mathematical models for flexible slewing structures-linear and nonlinear curvature (2001) Nonlinear Dynamics, Chaos and Their Applications to Engineering Sciences, 4: Recent Developments in Nonlinear Phenomena, pp. 372-382. , in: Balthazar, J.M., Gonçalves, P.B., Brasil, R.M.F.L.R.F., Caldas I.L. and Rizatto, F.B. (eds)Fenili, A., Balthazar, J.M., Mook, D.T., Weber, H.I., Application of the center manifold reduction to the slewing flexible non-ideal model (2002) J. Brazil. Soc. Mech. Sci., , (in press)Fenili, A., Balthazar, J.M., Mook, D.T., Some remarks about the experimental analysis of slewing flexible structures and mathematical modeling Proceedings of the Ninth International Symposium on Dynamic Problems of Mechanics, Florianópolis, SC, Brazil, 5-9 March 2001, pp. 341-346. , in: Espindola, J.J., Lopes, E.O.M. and Bazan, F.S.V. (eds)Fenili, A., Balthazar, J.M., Mook, D.T., A brief note on experimental identification of dc-motor parameters (2001) Sci. Eng. J., 10 (1), pp. 105-108Pontes, B.R., De Oliveira, V.A., Balthazar, J.M., On friction-driven vibrations in a mass block-belt-motor with limited power supply (2000) J. Sound Vib., 234 (4), pp. 713-723Pontes, B.R., De Oliveira, V.A., Balthazar, J.M., On the dynamic response of a mechanical system with dry friction and limited power supply (2001) Nonlinear Dynamics, Chaos and Their Applications to Engineering Sciences, 4: Recent Developments in Nonlinear Phenomena, pp. 355-371. , in: Balthazar, J.M., Gonçves P.B., Brasil, R.M.F.L.R.F., Caldas I.L. and Rizatto, F.B. (eds)Alifov, A., Frolov, K.V., Investigation of self-excited oscillations with friction, under conditions of parametric excitation and limited power of energy source (1977) Mekhanika Tvedogo Tela, 15 (4), pp. 25-33Warminski, J., Balthazar, J.M., Brasil, R.M.L.R.F., Vibrations of non-ideal parametrically and self-excited model (2001) J. Sound Vib., 234 (4), pp. 713-723De Souza, S.L.T., Caldas, I.L., Balthazar, J.M., Brasil, R.M.L.R.F., Analysis of regular and irregular dynamics of a non-ideal gear rattling problem (2002) J. Brazil. Soc. Mech. Sci., pp. 111-114Krasnopol'skaya, T.S., Shevts, A.Y., Chaotic interactions in a pendulum energy source system (1990) Prikladnaya Mekhanika, 26 (5), pp. 90-96Belato, D., Nonlinear analysis of non-ideals holonomic dynamical systems (2002), PhD Thesis, Faculdade de Engenharia Mecânica, UNICAMP, Campinas, São Paulo, Brazil(in Portuguese)Belato, D., Weber, H.I., Balthazar, J.M., Mook, D.T., Chaotic vibrations of a non-ideal electromechanical system (2001) Int. J. Solids Struct., 38, pp. 669-1706Palacios, J.F., Balthazar, J.M., Brasil, R.M.L.R.F., Some comments on a control technique by using internal resonance and saturation phenomenon: Applications to a simple machine foundation VII Pan American Congress of Applied Mechanics, Chile, Telmuco, 2002, pp. 141-144Brasil, R.M.L.R.F., Garzeri, F.J., Balthazar, J.M., An experimental study of the nonlinear dynamics of a portal frame foundation for a non-ideal motor Proceedings of DETC'01 ASME 2001 Design Engineering Technical Conference and Computers and Information in Engineering Conference, Pittsburgh, Pennsylvania, September 9-12, CD ROM, 200

Nonlinear dynamics and control strategies: On a energy harvester vibrating system with a linear form to non-ideal motor torquet

In this paper, we deal with the research of a vibrating model of an energy harvester device, including the nonlinearities in the model of the piezoelectric coupling and the non-ideal excitation. We show, using numerical simulations, in the analysis of the dynamic responses, that the harvested power is influenced by non-linear vibrations of the structure. Chaotic behavior was also observed, causing of the loss of energy throughout the simulation time. Using a perturbation technique, we find an approximate analytical solution for the non-ideal system. Then, we apply both two control techniques, to keep the considered system, into a stable condition. Both the State Dependent Ricatti Equation (SDRE) control as the feedback control by changing the energy of the oscillator, were efficient in controlling of the considered non-ideal system

Private bankers on private banking: financial risks and asset/liability management

The authors analyze private bankers’ views on the raison d’être of their profession, their clients’ main financial risks, and the professionals’ opinions on introducing asset liability management (ALM) to private banking. Although practitioners agree on the importance of tailored solutions for their clients’ primary risks such as unexpected inflation, they are not satisfied by the current risk management tools at hand to advise their clients, nor by the overall risk management service provided. Against this backdrop, this survey shows that ALM is considered to be a promising concept to strengthen advisory quality in private banking