Keywords: vibration, passive damping, resistive shunting, shear piezoceramics.

Since the first experimental demonstration, in the late seventies [1], of the possibility of the electronic passive damping of vibrations in optical bar-type structures, and its impedance-based theoretical formulation and experimental validation for beam-type structures in the early nineties [2], passive damping with shunted piezoceramics was the focus of many researches, in particular during the last decade [3,4,5,6]. The shunted damping is reached through the dissipation of the vibratory mechanical energy of the system via an electronic circuit shunting an attached piezoceramic patch that works in one of three modes [2]: (i) the transverse (or extension) mode which uses the strain piezoelectric coupling constant ; (ii) the longitudinal mode, exploiting the strain piezoelectric coupling constant ; and (iii) the shear mode, which uses the piezoelectric coupling constant . Each of these modes is associated to a characteristic electromechanical coupling coefficient (EMCC) that measures the conversion rate of the mechanical energy to electrical one and vice-versa. Table 1 indicates that the highest EMCC is generally that corresponding to the longitudinal mode, followed by that of the shear mode whereas the lowest is that corresponding to the classical extension mode. However, most investigations have been concerned mainly with the latter, followed by the longitudinal mode but, to the authors knowledge, the shear-mode has not yet been studied.

It is then the objective of this contribution to present, for the first time, simple theoretical and finite element investigations of the use of shear-mode piezoceramics for shunted passive vibration damping. Preliminary results for the first three modes of a vibrating aluminium beam with sandwiched (axially polarized) and surface-bonded (through-the-thickness polarized) piezoceramic patches indicate that: (i) as shown in Table 2, the added resistively Shear-mode Shunted Damping (SSD) is more than ten times the resistively Extension-mode Shunted Damping (ESD); (ii) as shown in Table 3, the amplitude reduction due to the SSD is more than three times that due to ESD.

The shunted damping can be used either alone, when low-to-medium damping is required, or combined with an active damping as a complementary or fail safe passive solution.

1

Forward, R.L., "Electronic damping of vibrations in optical structures", Applied Optics, 18, 690-697, 1979. doi:10.1364/AO.18.000690

2

Hagood, N.W., von Flotow, A., "Damping of structural vibrations with piezoelectric materials and passive electrical networks", Journal of Sound and Vibration, 146, 243-268, 1991. doi:10.1016/0022-460X(91)90762-9

3

Johnson, C.D., "Design of passive damping systems", ASME Journal of Vibration and Acoustics, 117, 171-176, 1995. doi:10.1115/1.2838659

4

Smith, C.A., Anderson, E.H., "Passive damping by smart materials: analysis and practical limitations", in "Proceedings of SPIE Conference on Smart Structures and Materials", Johnson, C., (Editor), SPIE, Washington, 2425, 136-148, 1995. doi:10.1117/12.208883

5

Lesieutre, G.A., "Vibration damping and control using shunted piezoelectric materials", Shock and Vibration Digest, 30, 187-195, 1998. doi:10.1177/058310249803000301

6

Ahmadian, M., DeGuilio, A.P., "Recent advances in the use of piezoceramics for vibration suppression", Shock and Vibration Digest, 33, 15-22, 2001. doi:10.1177/058310240103300102

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