Proposals for Controlling Flexible Rotor Vibrations by Means of an Antagonistic SMA/Composite Smart Bearing

Abstract:

Recent EPSRC funded research at Glasgow University, Swansea University, and Virginia Polytechnic and State University, and collaborative work with the Karlsruhe University of Applied Sciences, on the application of shape memory alloy (SMA) elements integrated within glass epoxy composite plates and shells is currently leading to the design of a novel smart bearing based on the principle of antagonistic action. In this system a ball bearing is fitted halfway down a glass epoxy composite tube, entering through one end of the tube. The tube has both ends rigidly built in to the support frame. The tube is divided into two regions, one on each side of the centrally located bearing. SMA strips are bonded in two independent sets of four, each set running axially along half the length of the tube and separated by 90 º around the tube. The four strips in each set are electrically connected in series to a high current power supply that can be switched in or out, and the current set, as required. This provides a convenient and fast way of heating each set of SMA strips through the martensite-to-austenite transformation temperature, and provides a significant axial contraction load on the tube in either direction. Previous FE analysis has provided predictions for converting an axial contraction load into useful stiffening of the structure in the radial and hoop directions. This introduces the potential for modification of the dynamic performance of the flexible rotor. In addition to separate heating each half of the active bearing has its own independent forced-air cooling system. Previous work by one of the authors, and others, has shown that a single SMA/composite active bearing can be very effective in both altering the natural frequency of the fundamental whirl mode as well as the modal amplitude. The drawback with that design has been the disparity in the time constant between the relatively fast heating phase and the much slower cooling phase which is reliant on forced air, or some other form of cooling. This form of design means that the cooling phase of one half, still using forced air, is significantly assisted by switching the other half into its heating phase, and vice versa, thereby equalising the time constants, and giving a faster push-pull load on the centrally located bearing; a loading which is termed ‘antagonistic’ in this paper. The experimental system is discussed in terms of potential performance and control issues.

• Periodical: Applied Mechanics and Materials (Volumes 5-6)
• Pages: 29-36
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.5-6.29
• Online since: October 2006
• Authors: Daniel J. Inman, Matthew P. Cartmell, A.W. Lees, Th. Leize, L. Atepor
• Keywords: Antagonistic Design, Flexible Rotor, Glass Epoxy Composite, Shape Memory Alloy Actuator, Vibration Control

References

[1] A.J. śak, M.P. Cartmell and W.M. Ostachowicz, Dynamics and Control of a Rotor Using and Integrated SMA/Composite Active Bearing Actuator, 5 th International Conference on Damage Assessment of Structures, 1-3 July 2003, University of Southampton, UK, pp.233-240, (2003).

DOI: 10.4028/www.scientific.net/kem.245-246.233

[2] D.J. Segalman, G.G. Parker and D.J. Inman, D. J., Vibration Suppression by Modulation of Elastic Modulus Using Shape Memory Alloy, in Intelligent Structures, Materials and Vibration, edited by M. Shahinpoor and H.S. Tzou, ASME Vol. 58, pp.1-5., (1993).

DOI: 10.1115/detc1993-0151

[3] H. Funakubo, H., Shape Memory Alloys, Gordon Breach Science Publications, NY., (1987).

[4] A.J. śak, M.P. Cartmell, W.M. Ostachowicz and M. Wiercigroch, One dimensional shape memory alloy models for use with reinforced composite structures, Smart Materials and Structures, Vol. 12, pp.338-346, (2003).

DOI: 10.1088/0964-1726/12/3/304

[5] A.J. śak and M.P. Cartmell, Analytical modelling of shape memory alloys and flat multilayered composite beams and plates with shape memory alloy wires, 1st Report, Grant GR/N06267/01, Dept. of Mechanical Engineering, Univ. of Glasgow, (2000).

[6] W.M. Ostachowicz, M.P. Cartmell and A.J. śak, Statics and dynamics of composite structures with embedded shape memory alloys, Adv. Course on Structural Control and Health Monitoring, Smart'01, 22-25 May 2001, Warsaw, pp.123-133, (2001).

[7] A.J. śak, M.P. Cartmell and W.M. Ostachowicz, Dynamics of multilayered composite plates with shape memory alloy wires, Journal of Applied Mechanics, Transactions of the ASME, Vol. 70, pp.185-212, (2003).

DOI: 10.1115/1.1546263

[8] A.J. śak, M.P. Cartmell, and W.M. Ostachowicz, Dynamics of multi-layered composite beams and plates with SMA wires, 2nd Report, EPSRC Grant GR/N06267/01, Department of Mechanical Engineering, University of Glasgow, (2001).

[9] M.I. Friswell, J.E.T. Penny, A.W. Lees and S.D. Garvey, Modelling and Computation in Rotordynamics, Cambrridge University Press, (2006).

[10] J. M. Vance, D. Ying, Experimental measurements of actively controlled bearing damping with an electrorheological fluid, Journal Of Engineering For Gas Turbines And PowerTransactions Of The Asme 122 (2): 337-344 Apr (2000).

DOI: 10.1115/1.483212

[11] M.O.T. Cole, P.S. Keogh, M.N. Sahinkaya and C.R. Burrows, Towards fault-tolerant active control of rotor-magnetic bearing systems, Control Engineering Practice 12 (4): 491-501 Apr (2004).

DOI: 10.1016/s0967-0661(03)00173-4