1,720,986 research outputs found
Hydrodynamic Model Of Valve Train Systems Support
No full textThe main objective of this research is to find the range of normal forces for a complete turn of the cam, depending on the axial tilting angle of the tappet to drive the tappet spin, minimising its wear effect. The valve train system used in combustion engines has the function of controlling the opening and closure of gas circulation valves, that takes part in combustion process. One of its systems is the rocker arm/hydraulic lash adjuster contact. The knowledge of this sub-system is important to wear and noise evaluation that come from this contact as well as friction evaluation for the command general optimisation. To reduce wear, the tappet must spin with respect to the rocker arm. The oil film around the tappet is represented by its pressure distribution, evaluated from the Reynolds Equation. Considering the friction and the moments generated by the axial tilting in the tappet, an equilibrium condition is reached, defining the tappet spin with respect to the rocker arm. Copyright © 2007 Inderscience Enterprises Ltd.4401/02/15167187Alexander, D., Fueling the next generation (2004) Automotive Engineering International - SAE International, 112 (9), pp. 73-77. , USA, Setembro, ppBartsch, H., (1993) Diplomarbeit - Untersuchung der Tassenrotation im Ventiltrieb mit Hydraulischen Tassenstössel aus Technische Universität Cheminitz - Zwickau, pp. 1-3Butenschön, H.J., (1976) Das Hydrodynamische, Zylindrische Gleitlager Endlicher Breite Unter Instationärer Belastung, pp. 35-50. , Dissertation Fakultät für Maschinenbau, Universität Karlsruhe, ppCarney, D., Internal-combustion engineering North America global viewpoints (2004) Automotive Engineering International, SAE International, 112 (5), pp. 39-46. , MaioCastro, H.F., Cavalca, K.L., Idehara, S.J., Updating method based on genetic algorithm applied to non-linear journal bearing model (2004) 8th International Conference on Vibrations in Rotating Machinery, I MEch E 2004, C623/091/2004, pp. 433-444. , Swansea, Wales, ppCavalca, K.L., Cattaruzi, E.F., A case tool dedicated to design of hydrodynamic bearings (2001) IJMEE - The International Bearing of Mechanical Engineering Education, 29 (4), pp. 361-380. , Mnachester, UKCavalca, K.L., Dedini, F.G., Experimental analysis of a tilting pad journal bearing influence in a vertical rotating system (1998) 5th International Conference on Rotor Dynamics, pp. 571-582. , IFTo MM, Darmstadt, Germany, ppCavalca, K.L., Lima, E.M., Análise não-linear de mancais hidrodinâmicos montados em um rotor vertical (1998) RBCM, Rio de Janeiro, 20 (2), pp. 244-262Cavalca, K.L., Idehara, S.J., Pederiva, R., Dedini, F.G., Experimental non-linear model updating applied in cylindrical journal bearing (2001) ASME-DETC, , Pittisburg, DETC 200 l/VIB-21549Gscheidle, R. (1998) Tabellenbuch Kraftfahrzeugtechnik, Verlag Europa-Lehrmittel, GmbH & Co., KG, Haan-Gruiten, Germany, pp.157-184Jacon, F.T.P., Cavalca, K.L., (2000) Linear Model Updating Applied to Rotating Machines, , SAE Technical Papers, Danvers MA, USA SAE Paper Number 2000-01-3189Kingsbury, A., On problems in the theory of fluid-film lubrication, with an experimental method of solution (1931) Transactions ASME, pp. 59-75Koç, E., An Investigation into the numerical solution of Reynolds lubrication equation with special reference to thrust bearings (1990) Tribology International, pp. 429-437Mastaler, A., Cavalca, K.L., (2003) Journal Bearings Applied in the Camshaft Support Elements for High Performance Engines, , Cobem, São Paulo, BrazilMastaler, A. and Cavalca, K.L. (2003b) Finite Difference Model for Journal Bearings Applied in the Camshaft Support Elements, 2003-01-3557 - SAE Technical Papers, São Paulo, BrazilMastaler, A., Cavalca, K.L., Journal bearing theory applied in the simulation camshaft behaviour (2004) XXV Cilamce 2004, pp. CIL21-CI034. , Recife- PE, BrazilMetzner, T., Becker, N., Demmelbauer-Ebner, W., Müller, R., Bach, M.W., Der neue 6-l-W12-Motor im Audi A8 (2004) MTZ- Motor Technische Zeitschrift, , April, DeutschlandPinkus, O., Analysis of elliptical journal bearing (1956) TRNAS. ASME, 78, pp. 965-973Pinkus, O., (1959) Analysis and Characteristics of Three-Lobe Journal Bearing of Basic Engineering, pp. 49-55Pischinger, S. (1994) 'Verbrennungsmotoren - Vorlesungsdruck band I und II - 15. Auflage', Lehrstuhl Fũr Nagewandte Thermodynamik Reinisch, Westfãlische Technische Hochschlule Aachen, Trans-aix-pressPischinger, S., Fahrzeugnatriebe der zukunft: Die Verbrennungskraftmaschine und ihre alternativen (1999) MTZ - Zukunft - Perspektiven des Verbrennungsmotors - Sonderheft 60 Jahre Motortechnische ZeitschriftReynolds, O., On the theory of lubrication and its application to Mr. Beauchamp Tower's experiments (1886) Included in Experimental Determination of the Viscosity of Olive Oil, p. 188Schmidt, A., (1995) Einfluss Tassenstösseldrehung auf die Reibung - und Schmierverhältnisse im System Nocken-Gegenläufer, pp. 12-17. , Dissertation Doktors-ingenieurs aus Clausthal-Zellerfeld, ppSinghal, G.C., Computation methods for hydrodynamic problems (Reynold's equation) (1981) Computer Aided Design, 13 (3), pp. 151-154Smith, G.D., (1987) Numerical Solution of Partial Differential Equations, pp. 1-79. , Clarendon Press Oxford-Hill Book Company, Oxford, UK, ppSpiegel, M.R., (1971) Schaum's Outline of Theory and Problems of Calculus of Finite Differences and Difference Equations, pp. 1-78. , McGraw-Hill Book Company, New York, USA, ppSternlicht, B., Maginniss, F.J., Application of digital computers to bearing design (1957) Transactions ASME, 79, pp. 1483-1493Weiser, H.P., Nordmnan, R., Development of labyrinth seals and gas journal bearing in high-performance - turbo machinery using finite difference techniques (1998) 5th IFToMM, pp. 252-261. , Darmstadt, ppBosch, R., (1999) Kraftfahr-technische Taschenbuch, 23, pp. 181-189. , Auflage, Vieweg, ppGreuter, E., Zima, S., (2000) Motorschaüden - Schäden na Verbrennungsmotoren und Deren Ursachen, pp. 336-366. , Vogel, ppJost, K., GM fuel cell for U.S. postal service (2000) Automotive Engineering International - SAE International, 112 (9), pp. 10-13. , USA, Setembro, ppKoühler, E., Verbrennungsmotoren - motormechanik, berechnung und auslegung des hubkolbenmotors (1998) Vieweg ATZ-MTZ-Fachbuch, pp. 277-309Kuüntscher, V., (1995) Kraftfahrzeugmotoren - Auslegung und Konstruktion, pp. 444-482. , Verlag Technik, Berlin, ppMaas, G., Mastaler, A., (2000) Continuous Improvement of Hydraulic Lash Adjusters Regarding Engine Performance, , SAE Technical Papers, 2000-01-3200, Sao Paulo, BrazilWolfle, M., Koss, A., Gasper, W., Utech, K., Rechs, M., Kunde, O., (1999) Die Neue Motorenbaureihe Von Ford Fur Den Einsatz in Schwellenlandern: Teil I: Grundmotor, MTZ, Motortechnische Zeitschrift, 60 (11), pp. 746-755. , Germany, ppWolfle, M., Muschen, A., Rechs, M., Kunde, O., Hoff, H., Die Neue Motorenbaureihe Von Ford Fuür Den Einsatz in Schwellenlandern (1999) System- UND Brennverfahrensentwicklung, MTZ, Motortechnische Zeitschrift, 60 (12), pp. 854-865. , Germany, p
Dynamic Analysis Of Flexible Gear Coupling Efforts In Rotating Machinery
No full textThis study presents an analysis of the efforts involved in a flexible coupling - gears coupling - based on analytical equations. It intends to evaluate system behavior due to the rotation variation, as well as the significant parameters in comparison to the hypotheses usually adopted. Copyright © 2002 Society of Automotive Engineers, Inc.Mancuso, J.R., Couplings and Joints - Design, Selection and Application, , 2nd Edition - Marcel Dekker, IncMancuso, J.R., (1971) Moments and Forces Imposed on Power Transmission Systems Due to Misalignment of A Crown Tooth Coupling, , The Pennsylvania State UniversityJune /Tapia, A.T., Cavalca, K.L., Efeito da Modelagem dos Acoplamentos Flexíveis nos Sistemas MecânicosCOBEM 2001, Anais Do CogressoFigueiredo, J.R., Sbravati, A., Silva, A.F.S., Favaro, C., Santos, R.G., Substitution- Newton-Raphson Method Applied to the Modeling of A Vapour Compression Refrigeration System Using Different Representations of the Thermodynamic Properties of R134
Finite Difference Model For Journal Bearings Applied In The Camshaft Support Elements
No full textThe modern passenger cars structure has the valve actuation system with usual application in combustion engines. These mechanisms offer the possibility to change the rotational movement into an oscillating movement, so this simple construction causes an elementary higher dynamic stiffness, but gives costs advantages in opposite of lever controls. Regarding the valve actuation over tribology view increase the cam / tappet friction losses. The friction forces had decreased considerably through the use of roller cam, which in comparison to cams and flat systems is possible to save up to 70% [17]. The friction increased in the camshaft / tappet system leads to an elevate heat stream, that must be derived from the contact with the complete system and the lubricant oil. The objective of this paper is to introduce the oil film pressure distribution in different boundary conditions, the modeling first part. Copyright © 2003 Society of Automotive Engineers, Inc.(1976), pp. 35-50. , Buteschön, Dipl. Math. Hans-Jürgen, "Dissertation Doktor-Ingenieur aus Universität Karlsruhe"Cattaruzzi, E.F., (1998), Mancais Hidrodinâmicos: Projeto, Dimensionamento e Aplicações"Cavalca, K.L., Cattaruzi, E.F., A CAE Tool Dedicated to Design of Hidrodynamic Berings (2001) IJMEE - The International Journal of Mechanical Engineering Education, 29 (4), pp. 361-380. , Manchester - UKCavalca, K.L., Idehara, S.J., Pederiva, R., Dedini, F.G., Experimental Non-Linear Model Updating Applied in Cylindrical Journal Bearings (2001) ASME-DETC, Pittisburg DETC 2001/VIB-21549Cavalca, K.L., Lima, E.M., (1998), 20 (2), pp. 244-262. , Análise Não-Linear de Mancais Hidrodinâmicos Montados em um Rotor Vertical" - RBCM, Rio de JaneiroCavalca, K.L., (2000), Modelagem e Análises de Máquinas Rotativas e Estrutura de Suporte" - UnicampIrretier, H., Lindemann, S., Improvement of Damping Parameters of Flexive Rotors by Experimental Model Analysis and Model Updating (2002) 6Th IFToMM, pp. 388-395. , SydneyJacon, T.P., Cavalca, K.L., Linear Model Updating Applied to Rotating Machines (2000) SAE Technical Papers, , http://www.sae.org/technical/papers/2000-01-3189, Danvers MA - USA SAE Paper number 2000-01-3189Koç, E., An Investigation into the numerical solution of Reynolds lubrication equation with special reference to thrust bearings (1990) Tribology International, pp. 429-437Maas, G., Mastaler, A., Continuous improvement of Hydraulic Lash Adjusters Regarding Engine Performance (2000) SAE Technical Papers, 2000-01-3200, , São Paulo - BrasilNorton, R.L., (1996) Machine Design, Prentice Hall Inc, pp. 648-656Pinkus, O., Analysis of elliptical bearings (1956) TRANS. ASME, 78, pp. 965-973Pinkus, O., (1959) Analysis and Characteristics of Three-Lobe Bearing, Journal of Basic Engineering, pp. 49-55Reynolds, O., On the Theory of Lubrication and its Application to Mr. Beauchamp Tower's Experiments (1886) Experimental Determination of the Viscosity of Olive Oil, p. 188. , included inSchmidt, A., (1995), pp. 12-17. , Dissertation Doktors-Ingenieurs aus Clausthal-Zellerfeld: Einfluss Tassenstösseldrehung auf die Reibung - und Schmierverhältnisse im System Nocken-Gegenläufer"Weiser, H.P., Nordmann, R., Development of Labyrinth Seals and Gas Bearings in High-Performance - Turbomachinery Using Finite Difference Techniques (1998) 5th IFToMM, pp. 252-261. , DarmstadtBartsh, C., (1994), Auch Zweiventil-Viertakter haben eine Zukunft" - Antriebstechnik 33, Nr. 10Holland, J., Schmidt, A., (1993), Stössel-Rotation im Nocken-Flashstössel-SystemTribologie and Schmierungstechnik 40, Nr. 1Mastaler, A., Cavalca, K.L., Journal Bearings Applied in the Camshaft Support Elements for High Performance Engines (2003) Cobem 200
Sensitivity Analysis Of Fault Tree (fta) In Gearboxes To Commercial Vehicles Using Reliability Concepts And Design Of Experiments
No full textThis work has as objective the construction of a reduced fault tree to gearboxes in commercial vehicles. In this reduction, the representative statistical model of reliability is studied for all the components that generate failures, where it is complemented with an application of factorial planning with two replicates to identify the components most sensible to the variation of the parameters in the reliability distributions. Thus, fault tree was constructed from the factors of scale (α) and form (β) for each component. From the data statistical models are obtained to individual failures, and the study of the degree of sensitivity of these components into system becomes viable by the reduction of the model of the FTA and applications of design of experiments. With these techniques, the FTA can be reduced as well as the number of failures around 30%, which contributes in the direction of the improvement of product's reliability, in this case, gearboxes. This procedure can be extended to other systems of a vehicle, allowing the statistics modeling of the system that contribute to the identification of the main components that are the cause or lead to the failures in specific kilometers. This methodology allows to a conception of a model for management of the actions of guarantee and descriptions for the development areas and production. In this model, it is possible to obtain information about time performance that assists in the activities of performance studies and optimization in design engineering. Copyright © 2005 Society of Automotive Engineers, Inc.Blashe, M.K., Shirivastava, B.A., Defining Failure of Manufacturing & Equipment (1994) Proceeding Annual Reliability and Maintainnability Symposium, pp. 69-75Cavalca, K.L., (2000) Apostila de Confiabilidade - IM461 Confiabilidade de Sistemas, p. 110. , Departamento de Projeto Mecânico, FEM, UNICAMPDoty, L.A., Reliability for the Technologies, p. 307. , New York: ASQC Quality Press Book. 1989Klutke, A critical look at the Bathtub Curve (2003) IEEE Transactions on Reliability, 52 (1). , March 2003Marques, D., Metodologia Para Ajuste e Comparação de Modelos de Confiabilidade, p. 2004. , Dissertação de mestrado, Departamento de projeto mecânico, FEM, Unicamp. 125Meeker, W.Q., Escobar, L.A., (1998) Statistical Methods for Reliability Data, p. 680. , John Wiley & Sons, IncMorello, M.G., Silveira, Z.C., Cavalca, K.L., A study of fault tree analysis in mechanical components of automobile industry (2004) SAE: Technical Papers, , São Paulo, SP, BrazilSilveira, Z.C., Cavalca, K.L., Statistical Analysis and Optimization of Design Parameters in Components of Rotating Machinery (2004) Proceedings of the Eighth International Conference on Vibrations in Rotating Machinery, IMechE 2004, pp. 615-626. , Swansea, Wales, UKRamakumar, R., Engineering Reliability: Fundamentals and Applications, p. 482. , Oklahoma: Prentice-Hall International, 199
Application Of The Confidence Level Concept In Reliability Analysis
No full textThe purpose of this software we developed was to make na analyses of the quality of mechanical components using reliability calculus. The computer program is a powerful tool, for it deals with failure tests, commonly used in practice to obtain the mean life, which is a fundamental parameter in advanced techniques of maintenance. Moreover, the work intends to make accessible concepts related to the reliability of systems and components in Mechanic Engineering, making possible a better understanding and familiarity. The subject is of great application in the great industries and projects with high levels of precision and security. What will determine the satisfaction of the customer after a component, and in consequence, its retention is the performance of its technique characteristics in the period of its life. The reliability, then, appears as a tool capable to define the probability that then product will play its functions foreseen for a period of time, under specific conditions of operation. How many products fail in its basic characteristics causing innumerable problems to the users and to the community? Thus, it is necessary to guarantee these basic aspects of the reliability through the analyses of the results generated by the software: the value of the probability, the time of use and therefore, the quality of the product. Copyright © 2002 Society of Automotive Engineers, Inc.Dedini, F.G., Cavalca, K.L., Projeto de Sistemas Mecânicos" apostila da disciplina EM964 do 5° ano do curso de graduação da Faculdade de Engenharia mecânica da UNICAMPPompas-Smith, J.H., (1973) Mechanical Survive - The Use of Reliability Data, , McGraw Hill, LondonLewis, E.E., (1996) Introduction to Reliability Engineering, , 2nd ed. New York: John Wiley & Sons IncDoty, L.A., (1989) Reliability for the Technologies, , Quality Press Book, New York(1997), Filho, V. B. "Confiabilidade Básica e Prática", Ed. Edgard Blücher Ltda, São PauloWerkema, M.C.C., (1996), 4. , Como estabelecer Conclusões com Confiança: entendendo inferência estatística", QFCO, Fundação Cristiano Ottoni, Belo HorizonteDrumond, B.F., (1996) Análise de Variância: Comparação de Várias Situações, 6. , et al, QFCO, Fundação Cristiano Ottoni, Belo HorizonteFreitas, M.A., (1997), 12. , Confiabilidade: análise de tempo de falha e testes de vida acelerados", QFCO, Fundação Cristiano Ottoni, Belo HorizonteRamakumar, R., (1993) Engineering Reliability - Fundamentals and Applications, , Prentice Hall International, New Jerse
Linear Model Updating Applied To Rotating Machines
No full textThe present research proposes the use of linear model updating along with unrestricted optimization methods, in order to obtain a methodology, which allows the calibration of mathematical models of rotating systems. An experimental set up of a symmetric rotor, on a rigid foundation supported by two hydrodynamic cylindrical bearings and with a central disk of considerable mass, working as an unbalancing excitation force, was used for this purpose. Once the numeric and experimental values are obtained, error vectors are then defined, which serve as minimization parameters, through the variation of the numeric model parameters. The method presented satisfactory results, as it was able to calibrate the mathematical model and then from that, obtain reliable responses for the physical system studied. The research also presents a significant contribution for the area of rotating machine design as it presents a relatively simple and robust methodology on the updating and revalidation of computational models for machines and structures. Copyright © 2000 Society of Automotive Engineers, Inc.Arruda, J.R.F., Rotor model updating by unbalance response curve-fitting (1989) 7 Th INTERNATIONAL MODAL ANALYSIS CONFERENCE, IMAC, 1989, 1, pp. 479-484. , Proceedings of New York: Union CollGirard, A., Chatelain, J., Bugeat, L.P., Model updating approach for rotating shafts (1997) 15 Th INTERNATIONAL MODAL ANALYSIS CONFERENCE, IMAC, 1997, 2, pp. 1419-1425. , Proceedings of New York: Union CollMoine, P., Billet, L., Aubry, D., Two updating methods for dissipative models with non symmetric matrices (1997) 15 Th INTERNATIONAL MODAL ANALYSIS CONFERENCE, IMAC, 1997, 2, pp. 1931-1936. , Proceedings of New York: Union CollAudebert, S., Multi-bearing rotor model updating using experimental modal and response data (1997) 15 Th INTERNATIONAL MODAL ANALYSIS CONFERENCE, IMAC, 1997, 1, pp. 162-168. , Proceedings of New York: Union CollChilds, D., (1993) Turbomachinery Rotordynamics -Phenomena, Modeling and Analysis, , New York: John Wiley & SonsCavalca, K.L., Dedini, F.G., Uemura, R., Mancais Hidrodinãmicos: Modelagem e Representação como elementos de conexão Rotor-Suportes-Fundação (1996) IV Congresso de Engenharia Mecânica Norte-Nordeste, , Recife, PEFriswell, M.I., Mottershead, J.E., (1996) Finite Element Model Updating in Structural Dynamics, , Netherlands: Kluwer Academic PublishersArora, J.S., (1989) Introduction to Optimum Design, , McGraw Hill International Editions, New YorkCavalca, K.L., Cavalcante, P.F., A method to analyse the interaction between rotor-foundation systems 16 Th INTERNATIONAL MODAL ANALYSIS CONFERENCE, IMAC, 1998, , Proceedings of Santa Barbara, USACheli, F., Cavalca, K.L., Dedini, F.G., (1992) Supporting Structure Effects on Rotating Machinery Vibrations, , Proceedings of Institute of Mechanical Engineers, Imech
Dynamic Analysis Of Flexible Couplings In Rotor-bearing-coupling Systems
No full textThe 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 3/1
Application Of Simulated Annealing Algorithm In The Reliability Optimization Of Redundant System
No full textThis work presents an application of the simulated annealing algorithm to redundant system reliability optimization, and its objective is to analyze this method and compare to other optimization methods, which are Genetic Algorithm, Evolution Strategy and Lagrange Multipliers. A hidrid optimization algorithm, composed by Simulated Annealing and Genetic Algorithm, is also developed in this work, to conciliate the advantages of both methods. The results presented by the Simulated Annealing and the hybrid algorithm are significant and validate these methods as robust tools for parameters optimization in engineering systems developments Copyright © 2004 Society of Automotive Engineers, Inc.Castro, H.F., Cavalca, K.L., Reliability Optimization of Redundant System (2002) SAE Technical Papers. In: CONGRESSO SAE BRASIL, 1, pp. 1-9. , São Paulo. Danvers MA USA: 2002Castro, H.F.D., (2003) Otimização da Confiabilidade e Disponibilidade em Sistemas Redundantes, p. 139. , Campinas, Faculdade de Engenharia Mecânica, Universidade Estadual de Campinas, Dissertação (Mestrado)Metropolis, N., Rosenbluth, A., Rosenbluth, M., Teller, A., Teller, E., Equation of State Calculations by Fast Computing Machines (1953) J. of Chem. Physics, 21Holland, J.H., (1975) Adaptation in Natural and Artificial System: An Introduction with Application to Biology, Control and Artificial Intelligence, , An Arbor, MI: University of Michigan PressRavi, V., Murty, B.S.N., Reddy, P.J., Nonequilibrium simulated annealing-algorithm applied to reliability optimization of complex systems (1997) IEEE Transactions on Reliability, 46 (2), pp. 233-239. , PII S0018952997055887Laarhoven, P.M., Aarts, E., (1989) Simulated Annealing: Theory and Applications, p. 187. , Dordrecht: KluwerKuo, W., Rajendra Prasad, V., An annotated overview of system-reliability optimization (2000) IEEE Transactions on Reliability, 49 (2), pp. 176-187. , PII S001895290010128
Availability Optimization With Genetics Algorithms [otimização Da Disponibilidade Com Algoritmos Genéticos]
No full textThis paper presents an availability optimization problem of an engineering series system, which has the redundancy of subsystems and the number of teams of maintenance as optimization parameters. The objective is to reach the maximum value of the availability, considering installation and maintenance cost, weight, volume and available maintenance teams as restrictions. The optimization method used was the Genetic Algorithm, which is based on biological concepts of species evolution. It is a robust method, because it does not converge to local optimum. It does not need the use of differential calculus, facilitating the computational implementation. The proposed search method (Genetic Algorithms) is easy to be implemented and suficinetly robust for the proposed problem. It reached the global optimum region with this method.1324754Doty, L.A., (1989) Reliability for the Technologies, , New York: ASQC Quality Press BookRamakumar, R., (1993) Engineering Reliability: Fundamentals and Applications, , Oklahoma: Prentice-Hall InternationalWohl, J.G., System operational readiness and equipment dependability (1966) IEEE Trans. Reliability, R-15 (1), pp. 1-6Lewis, E.E., (1987) Introduction to Reliability Engineering, , John & Wiley & Sons, IncHolland, J.H., (1975) Adaptation in Natural Artificial Systems, , University of Michigan PressHsieh, Y., Chen, T., Bricker, Genetic Algorithms for reliability design problems (1998) Microelectronics and Reliability, 38 (10), pp. 1599-1605Painton, L., Campbell, J., Genetic algorithm in optimization of system reliability (1995) IEEE Transactions on Reliability, 44 (1), pp. 63-72. , MarchGoldberg, D.E., (1989) Genetic Algorithm in Search Optimization and Machine Learning. Reading, , Mass.: Addison-WesleyMitchell, M., (1996) An Introduction to Genetic Algorithms, , Cambridge, MITMichalewicz, Z., (1996) Genetic Algorithm + Data Structure = Evolution Programs, , New York: SpringerCastro, H.F., (2003) Otimização da Confiabilidade e Disponibilidade em Sistemas Redundantes, , Universidade Estadual de Campinas - Dissertação de MestradoKumar, A., Pathak, R.M., Gupta, Y.P., Gemetic-algorithm-based reliability optimization for computer network expansion (1995) IEEE Transactions on Reliability, 44 (1), pp. 63-72. , MarchRubinstein, R.Y., Levitin, G., Lisnianski, A., Ben-Haim, H., Redundancy optimization of static series-parallel reliability models under uncertainty (1997) IEEE Transactions on Reliability, 46 (4), pp. 503-511. , DecemberLevitin, G., Redundancy optimization for multi-state system with fixed resource-requirements and unreliable sources (2001) IEEE Transactions on Reliability, 50 (1), pp. 52-59. , MarchHsieh, Y.C., Chen, T.C., Bricker, D.L., Genetic algorithms for reliability design problems (1998) Microeletronics Reliablity, 38 (10), pp. 1599-1605Coit, D.W., Smith, A.E., Reliability optimization of series-parallel system using a genetic alorithm (1996) IEEE Transactions on Reliability, 45 (2), pp. 254-266. , JuneYang, J., Hwang, M., Sung, T., Jin, Y., Application of genetic algorithm for reliability allocation in nuclear power plants (1999) Reliability' Engineering & System Safety, 65, pp. 229-238Taguchi, T., Yokota, T., Gen, M., Reliability optimal design problem with interval coefficients using hybrid genetic algorithms (1998) Computers and Industrial Engineering, 35 (1-2), pp. 373-376Castro, H.F., Cavalca, K.L., Reliability optimization of redundant system (2002) SAE Technical Papers, 1 (1), pp. 1-9. , Danvers MA USAErtas, A., (1993) The Engineering Design Process, p. 525. , John Wiley & Sons In
Identification Of A Rotating Machine Support Structure Through Mimo Technique
No full textLarge turbine sets are supported by several bearings, and these are connected to the structure foundation, which is usually made of steel and concrete. Besides, the structure is embedded in soil by concrete blocks or pillars, and the bearings work as dampers absorbing the vibration transmitted from rotor to foundation. This interaction affects both subsystems (rotor and foundation), and it is important to determine their dynamic behaviour. This work presents the application of a time domain method to calculate the modal parameters of a support structure of rotating machinery, used to include its influence on the dynamic behaviour of the rotor through the application of the Mixed Coordinates method, which uses modal coordinates of the structure and physical coordinates to the rotor-bearings subsystem. In order to test the modal analysis techniques, three techniques of excitation of the support structure were employed in a theoretical model: a single point excitation force applied by a shaker; a multi-point excitation where a set of shakers are connected to the structure; and a multi-point excitation generated by the unbalance of a rotor during its run-up and run-down. The MIMO techniques were also applied in a test rig that consists of a small rotor supported by a couple of plain journal bearings. Load cells were placed around the bearing cases to measure the forces applied to the structure, and there are accelerometers applied to the surface of the bearing case. This experimental data were used to calculate the modal parameters of the structure connection nodes, which were added to a rotor-bearings subsystem, where the rotor is represented by a Finite Element model, and the bearing coefficients are determined by the Finite Volume Method. A comparison was made between the experimental and simulation results of the identification techniques. © IMechE 2008.1331344Weber, H., (1961) Über das gemeinsame Schwingungsverhalten von Welle und Fundament bei Turbinenanlagen, (48), pp. 55-62. , VDI-BerichteGasch, R., Vibration of Large Turbo-Rotors in Fluid-Film Bearings on an Elastic Foundation (1976) Journal of Sound and Vibration, 47 (1), pp. 53-73Bachschmid, N., Bernante, R., Frigeri, C., Dynamic Analysis of a 660 MW Turbogenerator Foundation (1982) Proceedings of the International Conference Rotordynamic Problems in Power Plants, pp. 151-161. , Rome, Italia, ppDiana, G., Cheli, F., Vania, A., 1988, A method to identify the foundation modal parameters through measurements of the rotor vibrations, ImechE paper C300/88, Proceedings of the 5th International Conference on Vibrations in Rotating Machinery, Cambridge, UK, pp. 217-222Feng, N., Hahn, E.J., Experimental Identification of the Pedestals in a Rotor-Bearing-Pedestal System (1998) Proceedings of the 5 th International Conference on Rotor Dynamics, pp. 734-745. , IFToMM, Darmstadt, Germany, ppEdwards, S., Lees, A.W., Friswell, M.I., Experimental identification of excitation and support parameters of flexible rotor-bearings-foundation system from a single run-down (2000) Journal of Sound and Vibration, 232 (5), pp. 963-992Bachschmid, N., Pennacchi, P., Vania, A., Gregori, L., Zanetta, G. A., 2004, Unbalance identification in a large steam turbogenerator using model-based identification and modal foundation, ImechE paper C623-081, Proceedings of the 8th International Conference on Vibrations in Rotating Machinery, Swansea, UK, pp. 383-392Cavalca, K.L., Cavalcante, P.F., Okabe, E.P., An investigation on the influence of the supporting structure on the dynamics of the rotor system (2005) Mechanical Systems and Signal Processing, 19, pp. 157-174Okabe, E.P., Cavalca, K.L., Analysis of a theoretical-experimental model of a rotor-bearing-foundation system (2007) Proceedings of the 19th International Congress of Mechanical Engineering - COBEM, , Brasilia, Brazil, Paper DSS15-0732Gontier, C., Smail, M., Gautier, P.E., A time domain method for the identification of dynamic parameters of structures (1993) Mechanical Systems and Signal Processing, 7 (1), pp. 45-56Fassois, S.D., Lee, J.E., On the problem of stochastic experimental modal analysis based on multiple-excitation multiple-response data, part II: The modal analysis approach (1993) Journal of Sound and Vibration, 161 (1), pp. 57-87Moore, S.M., Lai, J.C.S., Shankar, K., ARMAX modal parameter identification in the presence of unmeasured excitation - I: Theoretical background (2007) Mechanical Systems and Signal Processing, 21, pp. 1601-1615Moore, S.M., Lai, J.C.S., Shankar, K., ARMAX modal parameter identification in the presence of unmeasured excitation - II: Numerical and experimental verification (2007) Mechanical Systems and Signal Processing, 21, pp. 1616-1641Fassois, S.D., MIMO LMS-ARMAX identification of vibrating structures - part I: The method (2001) Mechanical Systems and Signal Processing, 15 (4), pp. 723-735Florakis, A., Fassois, S.D., Hemez, F.M., MIMO LMS-ARMAX identification of vibrating structures - part II: A critical assessment (2001) Mechanical Systems and Signal Processing, 15 (4), pp. 737-758Ljung, L., (1999) System Identification: Theory for the User, , Prentice Hall, New Jersey, USA, 609 pNelson, H.D., A finite rotating shaft element using Timoshenko beam theory (1980) Journal of Engineering for Industry - Transactions of the ASME, 102, pp. 793-803Maliska, C.R., (2000) Heat transfer and computational fluid mechanics, , in Portuguese, Editora LTC, Rio de Janeiro, Brazil, 468 pPatankar, S.V., (1980) Numerical Heat Transfer And Fluid Flow, , Hemisphere Publishing, Washington DC, USA, 210 pEwins, D.J., (1995) Modal Testing: Theory and Practice, , Research Studies Press, Somerset, UK, 313 pPetsounis, K.A., Fassois, S.D., Parametric time-domain methods for the identification of vibrating structures - a critical comparison and assessment (2001) Mechanical Systems and Signal Processing, 15 (6), pp. 1031-106
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